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Biomedical subjects

M Bartoli

Publications and source records attributed to M Bartoli.

At least 19 recordsLinked to original sources
PubMed2006

Noninvasive monitoring of therapeutic gene transfer in animal models of muscular dystrophies.

Muscular dystrophies are a genetically and phenotypically heterogeneous group of degenerative muscle diseases. A subset of them are due to genetic deficiencies in proteins which form the dystrophin-associated complex at the membrane of the myofibers. In this report, we utilized recombinant adeno-associated virus containing a U7 cassette carrying an antisense sequence aimed at inducing exon skipping of the dystrophin gene or containing the alpha-sarcoglycan gene to alleviate the dystrophic phenotype of the mdx and Sgca-null mice, respectively. As these diseases are characterized by cycle of degeneration/regeneration, we postulated that a reporter gene coadministered at the time of the treatment would make it possible to follow the extent of muscle repair. We observed that the murine secreted alkaline phosphatase (muSeAP) level was very much lower in these animal models than in normal mice. Upon treatment of the dystrophic muscle by gene transfer, the level of muSeAP was restored and correlated with the expression of the therapeutic transgene and with the level of muscle improvement. The system described here provides a simple and noninvasive procedure for monitoring the outcome of a therapeutic strategy involving cell survival.

Alkaline Phosphatase↗
PubMed2006

Relationship between damage accrual, disease flares and cumulative drug therapies in juvenile-onset systemic lupus erythematosus.

Our objective was to investigate the pattern of damage accumulation in patients with juvenile-onset systemic lupus erythematosus (JSLE) and the relationship between damage accrual, disease flares and cumulative drug therapies. All patients with SLE followed prospectively in three tertiary care centres were identified. Only patients who presented within 12 months of diagnosis and were followed for at least three years were included. Damage was measures based on chart review using the SLICC/ACR damage index (SDI), which was modified (M-SDI) by adding the item growth failure. Mild-moderate and severe disease flares were defined by the increase in SLEDAI-2K. The cumulative duration of drug therapies was calculated in each patient. Fifty-seven patients were included. The mean M-SDI score for the whole patient group increased over time, from 0.1 at one year to 0.8 at three years to 1.5 at five years. Ocular and renal damage and growth failure were observed most frequently. Compared to patients with stable damage, patients who accrued new damage had a significantly greater frequency of severe disease flare in the first three years of follow-up. No significant difference was observed in any cumulative drug therapy between patients who accrued damage and those who did not. Damage accrual was associated with severe disease flares, suggesting that judicious use of immunosuppressive agents to achieve prompt control of severe exacerbation of disease activity is important in minimizing damage in patients with JSLE.

Adolescent↗
PubMed2005

Coagulase-positive Staphylococci and Staphylococcus aureus in food products marketed in Italy.

Staphylococcus aureus is a very common organism capable of producing several enterotoxins (SEs) that cause intoxication symptoms of varying intensity in humans when ingested through contaminated food. This paper reports the results of an investigation on the presence of Coagulase-Positive Staphylococci (CPS) and S. aureus in several food products marketed in Italy and on food contact surface swabs sampled from the food industry. A total of 11,384 samples were examined and 1971 of them (17.3%) were found to contain CPS. The assays performed on 541 CPS strains led to the identification of 537 S. aureus strains on which characterization of type A, B, C and D staphylococcal enterotoxins (SEA, SEB, SEC and SED) was performed. A total of 298 S. aureus strains (55.5%) produced one or more SEs: 33.9% of the strains produced SEC, 26.5% SEA, 20.5% SEA+SED, 13.4% SED, 2.7% SEB, 1.7% SEA+SEB, 0.7% SEC+SED and 0.3% produced SEA+SEC and SEB+SEC. The investigation highlighted that these organisms are very common and constitute a potential risk for consumers' health.

Coagulase↗
PubMed2005

Tools for evaluation of impact associated with MSW incineration: LCA and integrated environmental monitoring system.

The identification of significant pollutants emitted from the contamination source is the first step in evaluating the impact associated with anthropic activity. Municipal solid waste (MSW) incinerators are still generally perceived as great pollutant sources, in particular due to their gaseous emissions from the stack, which constitute the major effluent from the plant. In this work a life cycle assessment and an integrated environmental monitoring system were applied together, in order to obtain complete information about the incineration process and its environmental impact. The former is a proven methodology, but its application to waste management systems constitutes a relatively new field of application with a great developmental potential. The contribution of the incineration process to the different environmental impact categories was investigated, finding many avoided impacts due to energy recovery. The latter is an innovative approach that allows a remarkable understanding of impact due to a contamination source; interesting correlations were found between heavy metals both in gas emissions and in natural matrices in the surroundings.

Air Pollutants↗
PubMed2002

Application of an integrated environmental monitoring system to an incineration plant.

An integrated environmental monitoring system is an innovative approach which allows remarkable understanding of impacts due to a contamination source. Here we report results from environmental monitoring near a typical Italian incinerator plant. By means of mathematical dispersion models, zones of maximum pollutant depositions were determined; according to these simulations, a defined monitoring network was established. Heavy metals, chosen as environmental indicators, showed a wide flux range in gas emissions from the incinerator, over different sampling years. In particular, emissions in the year 2000 were marked by high Pb and Cd concentrations. Correspondingly, soil samples also exhibited a greater concentration of the same metals in 2000, than in previous years. Principal component analysis allowed a better visualisation of these similarities, also showing an interesting correlation between heavy metals observed both in gas emissions and in soil samples. Soil distant from the incinerator was found to be less affected by heavy metal contamination. Also atmospheric wet and dry depositions indicated a significant dependence on distance from incinerator, though extremely variable metal fluxes were registered during different months. Finally, vegetation samples, seasonal or evergreen, did not provide evidence of a significant heavy metal enrichment, apart from an apparent dependence on contamination source distance.

Air Movements↗
PubMed2001

Striatin, a calmodulin-dependent scaffolding protein, directly binds caveolin-1.

Caveolins are scaffolding proteins able to collect on caveolae a large number of signalling proteins bearing a caveolin-binding motif. The proteins of the striatin family, striatin, SG2NA, and zinedin, are composed of several conserved, collinearly aligned, protein-protein association domains, among which a putative caveolin-binding domain [Castets et al. (2000) J. Biol. Chem. 275, 19970-19977]. They are associated in part with membranes. These proteins are mainly expressed within neurons and thought to act both as scaffolds and as Ca(2+)-dependent signalling proteins [Bartoli et al. (1999) J. Neurobiol. 40, 234-243]. Here, we show that (1) rat brain striatin, SG2NA and zinedin co-immunoprecipitate with caveolin-1; (2) all are pulled down by glutathione-S-transferase (GST)-caveolin-1; (3) a fragment of recombinant striatin containing the putative caveolin-binding domain binds GST-caveolin-1. Hence, it is likely that the proteins of the striatin family are addressed to membrane microdomains by their binding to caveolin, in accordance with their putative role in membrane trafficking [Baillat et al. (2001) Mol. Biol. Cell 12, 663-673].

Animals↗
PubMed2001

Interactions of the rapsyn RING-H2 domain with dystroglycan.

Rapsyn, a peripheral membrane protein of skeletal muscle, is necessary for the formation of the highly organized structure of the vertebrate neuromuscular junction. For mice lacking rapsyn, there is a failure of postsynaptic specialization characterized by an absence of nicotinic acetylcholine receptors (nAChRs) and other integral and peripheral membrane proteins such as beta-dystroglycan and utrophin. Dystroglycan is necessary for the formation of the mature neuromuscular junction and has been shown to interact directly with rapsyn. Previous studies with rapsyn fragments and mutants, expressed in 293T cells along with nAChRs, establish that the rapsyn tetratricopeptide repeat (TPR) domain is involved in self-association and its coiled-coil domain is necessary for nAChR clustering. The function of the rapsyn RING-H2 domain, which is not necessary for rapsyn self-association or nAChR clustering, is unknown. To further characterize these domains, we have used a yeast two-hybrid assay to test for interactions at the plasma membrane between rapsyn domains and a nAChR beta-subunit fragment, the beta-dystroglycan cytoplasmic domain, or rapsyn domains. The rapsyn coiled-coil domain interacts with the nAChR beta-subunit cytoplasmic domain, but not with itself, other rapsyn domains, or beta-dystroglycan. The RING-H2 domain interacts only with the beta-dystroglycan cytoplasmic domain. Furthermore, when expressed in 293T cells, a rapsyn construct containing as few as two TPRs and the RING-H2 domain self-associates and clusters dystroglycan, but not nAChRs. These results emphasize the modular character of the rapsyn structural domains.

Amino Acid Motifs↗
PubMed2001

Reduced severity of oxygen-induced retinopathy in eNOS-deficient mice.

PURPOSE: Exposure of premature human infants to hyperoxia results in the obliteration of developing retina capillaries, leading to a vision-threatening retinopathy termed retinopathy of prematurity (ROP). The authors hypothesized that this process may be mediated in part by endothelial nitric oxide (NO)-derived oxidants such as peroxynitrite and tested this hypothesis in a mouse model of ROP. METHODS: Normal mice, mice treated with the nitric oxide synthase (NOS) inhibitor N:(G)-nitro-L-arginine (L-NNA), and knockout mice carrying a homozygous targeted disruption of the gene for endothelial NOS (eNOS) were studied in an experimental model of ROP. Retinas were compared for extent of capillary obliteration in hyperoxia, vascular endothelial growth factor (VEGF) expression, nitrotyrosine formation, and vitreous neovascularization. RESULTS: Oxygen-induced retinal vaso-obliteration was significantly reduced by L-NNA treatment (43% decrease from controls). The eNOS-deficient mice showed a similar reduction in vaso-obliteration (46% decrease from controls), and vitreous neovascularization was also substantially reduced (threefold decrease). Retinal nitrotyrosine formation, a measure of in situ peroxynitrite modification of proteins, was significantly elevated in normal mice during hyperoxia, in a spatial and temporal pattern consistent with a role in oxygen-induced vaso-obliteration. This was not seen in eNOS-deficient mice. VEGF expression was similar in both groups of mice, although suppression in hyperoxia was slightly blunted in eNOS-deficient mice. CONCLUSIONS: These data suggest a role for NO and peroxynitrite in the pathogenesis of ROP. Therapies aimed at modulation of eNOS activity may have therapeutic potential for preventing ROP.

Animals↗
PubMed2000

Vascular endothelial growth factor activates STAT proteins in aortic endothelial cells.

Vascular endothelial growth factor (VEGF) intracellular signaling in endothelial cells is initiated by the activation of distinct tyrosine kinase receptors, VEGFR1 (Flt-1) and VEGFR2 (Flk-1/KDR). Because the tyrosine kinase-dependent transcription factors known as STAT (signal transducers and activators of transcription) proteins are important modulators of cell growth responses induced by other growth factor receptors, we have determined the effects VEGF of on STAT activation in BAEC (bovine aortic endothelial cells). Here, we show that VEGF induces tyrosine phosphorylation and nuclear translocation of STAT1 and STAT6. VEGF also stimulates STAT3 tyrosine phosphorylation, but nuclear translocation does not occur. We found that placenta growth factor, which selectively activates VEGFR1, has no effect on the STATs. However, upon VEGF stimulation, STAT1 associates with the VEGFR2 in a tyrosine kinase-dependent manner, indicating that VEGF-induced STAT1 activation is mediated primarily by VEGFR2. Thus, our study shows for the first time that VEGF activates the STAT pathway through VEGFR2. Because the growth-promoting activity of VEGF depends upon VEGFR2 activation, these findings suggest a role for the STATs in the regulation of gene expression associated with the angiogenic effects of VEGF.

Animals↗
PubMed2000

Multiple-injection axillary brachial plexus block: A comparison of two methods of nerve localization-nerve stimulation versus paresthesia.

UNLABELLED: We conducted this prospective study to compare the onset time and the success rate of a multiple-injection axillary brachial plexus block performed by using two methods of nerve localization: paresthesia elicitation or nerve stimulation. Each of the major nerves of the plexus was located by elicitation of a paresthesia (Group PAR; n = 50) or by nerve stimulation (Group PNS; n = 50) and injected with 10 mL of local anesthetic solution. Time to perform the block, onset time of the primary block, time to achieve readiness for surgery, and total anesthetic time were significantly shorter in Group PNS than in Group PAR. The incidence of complete block was larger in Group PNS than in Group PAR (91% vs 76%; P: < 0. 05), and this was related to a larger success rate for anesthetizing the radial and the musculocutaneous nerves (P: < 0.05). The frequency of venous puncture was larger in Group PAR (P: < 0.05). For multiple-injection axillary brachial plexus block, we conclude that nerve stimulation resulted in a greater success rate and a faster onset than paresthesia elicitation, and it should be considered when the radial and musculocutaneous nerve distributions are involved in the surgical area. IMPLICATIONS: Two methods of nerve localization were compared when performing an axillary brachial plexus block by the multiple-injection technique. Nerve stimulation provided a faster onset and a greater incidence of complete block, related to a better success rate for anesthetizing the radial and the musculocutaneous nerves, than paresthesia elicitation.

Analgesia↗
PubMed2000

Effects of long-term treatment with verapamil on left ventricular function and myocardial blood flow in patients with dilated cardiomyopathy without overt heart failure.

Myocardial blood flow (MBF) abnormalities are present in early stage dilated cardiomyopathy (DCM) and have been attributed to coronary microvascular abnormalities. The favorable effects of verapamil on coronary microcirculation might indicate its use in early stage DCM. We assessed the safety of long-term combination therapy of verapamil and enalapril and its effects on both left ventricular function and myocardial perfusion compared with enalapril alone in 18 patients with DCM (15 men, 3 women; mean age, 50+/-9 years) without overt heart failure (NYHA class I-II). At baseline and after 6 months of randomized treatment with either enalapril (10-20 mg) (nine patients, group 1) or enalapril (10-20 mg) and verapamil (120-240 mg) (nine patients, group 2), left ventricular function was assessed at rest, during handgrip, and during bicycle exercise by equilibrium radionuclide angiography. Mean MBF was measured at rest and after dipyridamole by positron emission tomography (PET) and 13N-ammonia as a flow tracer. At baseline, the two groups had reduced left ventricular ejection fraction at rest, which was further impaired during isometric exercise, but increased at peak bicycle exercise. MBF was similarly reduced in the two groups at rest and during dipyridamole. During treatment, no adverse events occurred in either group. After 6 months there was no significant difference in the main study variables either between the two groups or within each group before and after treatment. Long-term combination therapy with verapamil and enalapril is safe in patients with DCM without overt heart failure. Despite no favorable effect on myocardial perfusion, combined treatment prevented deterioration of left ventricular function, similarly to enalapril alone.

Calcium Channel Blockers↗
PubMed1999

Down-regulation of striatin, a neuronal calmodulin-binding protein, impairs rat locomotor activity.

Striatin, an intraneuronal, calmodulin-binding protein addressed to dendrites and spines, is expressed in the motor system, particularly the striatum and motoneurons. Striatin contains a high number of domains mediating protein-protein interactions, suggesting a role within a dendritic Ca(2+)-signaling pathway. Here, we explored the hypothesis of a direct role of striatin in the motor control of behaving rats, by using an antisense strategy based on oligodeoxynucleotides (ODN). Rats were treated by intracerebroventricular infusion of a striatin antisense ODN (A-ODN) or mismatch ODN (M-ODN) delivered by osmotic pumps over 6 days. A significant decrease in the nocturnal locomotor activity of A-ODN-treated rats was observed after 5 days of treatment. Hypomotricity was correlated with a 60% decrease in striatin content of the striata of A-ODN-treated rats sacrificed on day 6. Striatin thus plays a role in the control of motor function. To approach the cellular mechanisms in which striatin is involved, striatin down-regulation was studied in a comparatively simpler model: purified rat spinal motoneurons which retain their polarity in culture. Treatment of cells by the striatin A-ODN resulted in the impairement of the growth of dendrites but not axon. The decrease in dendritic growth paralleled the loss of striatin. This model allows analysis of the molecular basis of striatin function in the dynamic changes occurring in growing dendrites, and offers clues to unravel its function within spines.

Animals↗
PubMed1998

Interaction of calmodulin with striatin, a WD-repeat protein present in neuronal dendritic spines.

Rat striatin, a quantitatively minor protein belonging to the WD-repeat family of proteins, is a Ca2+/calmodulin-binding protein mostly expressed in the striatum and in the motor and olfactory systems (Castets, F., Bartoli, M., Barnier, J. V., Baillat, G., Salin, P., Moqrich, A., Bourgeois, J. P., Denizot, F., Rougon, G., Calothy, G., and Monneron, A. (1996) J. Cell. Biol. 134, 1051-1062). Generally associated with membranes, striatin is mostly found in dendritic spines where it is likely to play a role in Ca2+-signaling events. In this paper, we characterize its calmodulin-binding properties. By using deletion mapping and site-directed mutagenesis, we identified the sequence located between amino acids 149 and 166 as the main calmodulin-binding site. The predicted corresponding peptide is potentially able to form a basic amphiphilic helix, as is often the case for many known calmodulin-binding sites. Calmodulin binding to striatin is Ca2+-dependent, with half-maximal binding occurring around 0.5 microM free Ca2+. In the presence of Ca2+, the equilibrium dissociation constant of calmodulin/striatin fusion protein complex is 40 +/- 5 nM. We also show that brain striatin subcellular localization, as studied by tissue fractionation, is Ca2+-dependent, this effect being probably mediated by calmodulin. Our results are in agreement with the hypothesis that striatin is a transducer involved in Ca2+ signaling or an adapter protein involved in regulating macromolecular assemblies within dendritic spines.

Amino Acid Sequence↗
PubMed1998

Distribution of striatin, a newly identified calmodulin-binding protein in the rat brain: an in situ hybridization and immunocytochemical study.

Striatin, a 110-kDa protein, is the first member of the tryptophane-aspartate repeat protein family known to bind calmodulin in the presence of Ca2+. We examined the distribution of striatin and its mRNA in the rat central nervous system (CNS) by using immunocytochemistry and in situ hybridization, respectively. Striatin immunostaining and mRNA labeling patterns are generally concordant. Regions showing the most intense staining are the dorsal striatum, nucleus accumbens (anterior and shell parts), olfactory tubercle, red nucleus, subthalamic nucleus, cranial nerve motor nuclei, and layer IX of the spinal cord (motoneurons). Low levels of both striatin and its mRNA are detected in the cerebral cortex, thalamus, septum, amygdala, hippocampus, midbrain and cerebellum. Striatin-immunoreactive neuronal processes are found predominantly in the structures containing striatin-positive neurons, suggesting that these labeled processes represent dendritic arborization rather than axonal processes. Except for the medial forebrain bundle, all axonal fiber tracts examined are devoid of striatin immunolabeling. These data show that the somatodendritic localization of striatin, previously described in the striatum, may be a main feature of the subcellular distribution of this protein throughout the CNS. Although widely distributed in neurons throughout the rat CNS, striatin is expressed prominently in the structures belonging to the motor system, suggesting that this protein may play a preponderant role in motor control.

Animals↗
PubMed1998

Cloning of human striatin cDNA (STRN), gene mapping to 2p22-p21, and preferential expression in brain.

Rat striatin, a recently discovered calmodulin-binding protein belonging to the WD repeat family, is expressed in neurons, mostly in the striatum and motor and olfactory systems. Striatin is localized in the somato-dendritic compartment of neurons, mainly in the spines. It may play a role in dendritic Ca2+ signaling. Here we report the cloning and sequencing of human striatin cDNA (HGMW-approved symbol STRN), the localization of the gene to chromosome 2p22-p21, and its preferential expression in brain. The human cDNA sequence is predicted to encode a 780-amino-acid protein possessing eight WD repeats. Striatin is highly conserved between rat and human with 96% identity and 98% similarity at the amino acid level. Since the Caenorabditis elegans genome also contains a closely related striatin coding sequence, the function of striatin is likely to be well conserved.

Amino Acid Sequence↗
PubMed1998

Relationships between striatin-containing neurons and cortical or thalamic afferent fibres in the rat striatum. An ultrastructural study by dual labelling.

Striatin, a recently isolated rat brain calmodulin-binding protein belonging to the WD-repeat protein family, is thought to be part of a calcium signal transduction pathway presumably specific to excitatory synapses, at least in the striatum. This study was aimed to specify the cellular and subcellular localization of striatin, and to determine the possible synaptic relationships between the two main excitatory afferent pathways, arising from the cerebral cortex and the thalamus, and the striatin-containing elements, in the rat striatum. Anterograde tract-tracing by means of biotinylated dextran amine injection in the frontoparietal cerebral cortex or the parafascicular nucleus of the thalamus was combined with immunogold detection of striatin. Striatin-immunoreactivity was confined to the neuronal somatodendritic compartment, including spines. Whereas 90-95% of the striatal neurons were striatin-positive, only about 50% of the sections of dendritic spines engaged in asymmetrical synaptic contacts exhibited striatin labelling. Among the sections of striatin-immunopositive dendritic spines, the number of immunogold particles ranged from one to more than seven, indicating an heterogeneity of the spine labelling. Moreover, within each class of spines presenting at least two silver-gold particles, the distribution of the particles varied from a clear-cut alignment under the postsynaptic densities (24-33% of spines) to a location distant from the synaptic area. In the cell bodies and dendrites, striatin labelling was usually not associated with the cytoplasmic membrane nor with the postsynaptic densities. In the striatum ipsilateral to the tracer injections, only 34.8% of the synaptic contacts formed by corticostriatal afferents involved striatin-positive elements (slightly labelled dendritic spines), whereas 56.7% of the synaptic contacts formed by thalamostriatal boutons were made on striatin-positive targets (mostly dendrites). In both cases, striatin labelling was usually not associated with the postsynaptic density. Most of the immunoreactive dendritic spines were in contact with unidentified afferents. These data reveal that striatin is expressed in the vast majority of the cell bodies of striatal spiny neurons, but is heterogeneously distributed among the dendritic spines of those neurons. Data also indicate a preferential relationship between striatin-containing structures and afferents from the parafascicular thalamic nucleus with respect to the frontoparietal cerebral cortex. But, at the dendritic spine level, striatin may be involved in signal transduction mechanisms involving as yet unidentified excitatory afferents to striatal neurons.

Afferent Pathways↗
PubMed1997

Transfer of macromolecules into living adult cardiomyocytes by microinjection.

Among techniques commonly used to deliver bioactive molecules into living cells, microinjection is a very efficient method. Microinjection has been used extensively for gene transfer into different cell types. We applied the microinjection technique to the adult rat ventricular cardiac muscle cells (AVC) in primary culture and optimized microinjection parameters and the appropriate cell culture conditions. We also optimized the use of particular agents (i.e. 2,3-butanedione monoxime, verapamil) for the prevention of the cell damage caused by the micropuncture. We obtained the expression of a CMV-beta-galactosidase reporter gene in up to 20% of the injected cells with efficient maintenance of long term cell viability. Under our experimental conditions direct microinjection is a very advantageous technique to transfer macromolecules into living adult cardiac muscle cells and a powerful system to study and manipulate the biochemistry and molecular biology of the cardiac myocyte.

Age Factors↗