Latest PUBLICATIONS

  • Multidirectional transpositions suggesting pathologic approach behavior after frontal stroke.
    Publication Date: 10/05/2005, on Neurology
    by Lepore M, Conson M, Grossi D, Trojano L
    DOI: 10.1212/01.WNL.0000160398.27467.C0

    The authors report a patient with a right frontal stroke who, despite the ability to draw clocks accurately from memory, translocated numbers on the inferior half of the dial to the superior half when copying a clock. In further graphic and verbal clock reproduction tasks, transpositions were always directed toward the model but disappeared in a delayed copying task. These findings appear to reflect an intentional disorder characterized by pathologic approach behavior.

  • Genotype-phenotype correlation in Italian families with Stargardt disease.
    Publication Date: 01/05/2005, on Ophthalmic research
    by Simonelli F, Testa F, Zernant J, Nesti A, Rossi S, Allikmets R, Rinaldi E
    DOI: 10.1159/000086073

    Autosomal recessive Stargardt disease (STGD) has been associated with substantial genetic and phenotypic heterogeneity. By systematic clinical analyses of STGD patients with complete genetic data (i.e. identified mutations on both alleles of the ABCA4 gene), we set out to determine phenotypic subtypes and to correlate these with specific ABCA4 alleles. Twenty-eight patients from 18 families with STGD/fundus flavimaculatus were investigated. All patients were submitted to complete ophthalmologic examination, electrophysiology, fluorescein angiography and ABCA4 gene chip analysis. Two main clinical phenotypes were observed among the examined patients. The severe phenotype was characterized by the onset of the disease <20 years and reduced ERG response, whereas the mild phenotype presented with later onset of the disease and a normal ERG response. Genetic analysis of the ABCA4 gene revealed, in the severe group, more frequently deletions, stop codons and insertions as compared to the mild phenotype group (p=0.0113 by Fisher's exact test). Moreover, the compound heterozygous mutations G1961E/5018+2T-->C found in 7 patients from 3 unrelated STGD families were associated with a mild phenotype in all subjects, except 1. This study documented variability of the clinical expression of STGD in relation to the age of onset of the disease, fundus appearance and the ERG response and allowed to subdivide patients into a severe and a mild phenotype group. These findings suggest that an extensive and comprehensive genetic analysis of STGD patients combined with thorough clinical evaluation, including the careful recording of the age of onset of the disease, would allow a more precise prognostic evaluation.

  • c-Myc antisense oligonucleotides preserve smooth muscle differentiation and reduce negative remodelling following rat carotid arteriotomy.
    Publication Date: 01/05/2005, on Journal of vascular research
    by Forte A, Galderisi U, De Feo M, Gomez MF, Esposito S, Santè P, Renzulli A, Agozzino L, Hellstrand P, Berrino L, Cipollaro M, Cotrufo M, Rossi F, Cascino A
    DOI: 10.1159/000085379

    The vascular biology of restenosis is complex and not fully understood, thus explaining the lack of effective therapy for its prevention in clinical settings. The role of c-Myc in arteriotomy-induced stenosis, smooth muscle cell (SMC) differentiation and apoptosis was investigated in rat carotids applying full phosphorothioate antisense (AS) oligonucleotides (ODNs).

  • A y(+)LAT-1 mutant protein interferes with y(+)LAT-2 activity: implications for the molecular pathogenesis of lysinuric protein intolerance.
    Publication Date: 01/05/2005, on European journal of human genetics : EJHG
    by Sperandeo MP, Paladino S, Maiuri L, Maroupulos GD, Zurzolo C, Taglialatela M, Andria G, Sebastio G
    DOI: 10.1038/sj.ejhg.5201376

    Lysinuric protein intolerance (LPI) is an inherited aminoaciduria caused by defective cationic amino acid (CAA) transport at the basolateral membrane of epithelial cells in the intestine and kidney. The SLC7A7 gene, mutated in LPI, encodes the y(+)LAT-1 protein, which is the light subunit of the heterodimeric CAA transporter in which 4F2hc is the heavy chain subunit. Co-expression of 4F2hc and y(+)LAT-1 induces the y(+)L activity. This activity is also exerted by another complex composed of 4F2hc and y(+)LAT-2, the latter encoded by the SLC7A6 gene and more ubiquitously expressed than SLC7A7. On the basis of both the pattern of expression and the transport activity, y(+)LAT-2 might compensate for CAA transport when y(+)LAT-1 is defective. By expression in Xenopus laevis oocytes and mammalian cells, we functionally analysed two SLC7A7 mutants, E36del and F152L, respectively, the former displaying a partial dominant-negative effect. The results of the present study provide further insight into the molecular pathogenesis of LPI: a putative multiheteromeric structure of both [4F2hc/y(+)LAT-1] and [4F2hc/y(+)LAT-2], and the interference between y(+)LAT-1 and y(+)LAT-2 proteins. This interference can explain why the compensatory mechanism, that is, an increased expression of SLC7A6 as seen in lymphoblasts from LPI patients, may not be sufficient to restore the y(+)L system activity.

  • Primary cerebral toxoplasmosis: a rare case of ventriculitis and hydrocephalus in AIDS.
    Publication Date: 01/05/2005, on Clinical neuropathology
    by Sell M, Klingebiel R, Di Iorio G, Sampaolo S
    DOI:

    We describe the clinical, radiological and neuropathological findings in an adult AIDS patient presenting with ventriculitis and hydrocephalus as the primary manifestations of cerebral toxoplasmosis. Clinical symptoms including fever, headache, changes in mental status and focal neurological deficits were non-specific. Cranial computed tomography showed a subtile ventricular dilatation whereas magnetic resonance imaging disclosed triventricular hydrocephalus due to stenosis of the aqueduct and a periventricular nodular rim of high signal intensity on T2- and proton density-weighted images. This rim also showed a slight enhancement on post-contrast T1-weighted images. Focal intracerebral lesions could not be delineated, neither by neuroimaging nor by pathology. Neuropathological examination showed severe ventriculitis with large ependymal and subependymal necrosis as well as dilatation of the lateral and the third ventricle. The only microorganism demonstrated at histology in the central nervous system was Toxoplasma gondii. We conclude that ventriculitis and hydrocephalus without any focal parenchymal lesion may be the only manifestations of CNS toxoplasmosis. It is important to recognize this unusual form of presentation of cerebral toxoplasmosis in order to perform specific therapy.

  • Autosomal dominant hereditary spastic paraplegia: DHPLC-based mutation analysis of SPG4 reveals eleven novel mutations.
    Publication Date: 01/05/2005, on Human mutation
    by Patrono C, Scarano V, Cricchi F, Melone MA, Chiriaco M, Napolitano A, Malandrini A, De Michele G, Petrozzi L, Giraldi C, Santoro L, Servidei S, Casali C, Filla A, Santorelli FM
    DOI: 10.1002/humu.9340

    We set up a new denaturing high-performance liquid chromatography (DHPLC)-based protocol to screen patients with autosomal dominant hereditary spastic paraplegia (AD-HSP) for mutations in SPG4. Six patients had a complicated form and 49 a pure HSP phenotype. We also analyzed 19 unrelated patients presenting with an HSP phenotype (pure in 17 and complicated in two subjects) but no clear family history, as such patients may be cases of dominant inheritance with low penetrance. The overall frequency of SPG4 mutations in our study of HSP (in which prior linkage data were unavailable) was 32.4%, rising to 46.9% when only pure AD-HSP patients were considered. This figure falls well within the range reported in different populations. Rather as expected, the clinical data available for the patients did not support an easy genotype-phenotype correlation. Moreover, the clinical picture was not influenced by the length of the predicted residual gene product. As well as identifying novel variants in SPG4, this study constitutes the molecular characterization of the largest cohort of Italian AD-HSP patients studied to date. In addition, it provided an efficient, cost-effective, and reliable detection protocol for mutational screening of SPG4, which might facilitate medical genetic counseling.

  • Differential carnitine/acylcarnitine translocase expression defines distinct metabolic signatures in skeletal muscle cells.
    Publication Date: 01/05/2005, on Journal of cellular physiology
    by Peluso G, Petillo O, Margarucci S, Grippo P, Melone MA, Tuccillo F, Calvani M
    DOI: 10.1002/jcp.20239

    Import of acylcarnitine into mitochondrial matrix through carnitine/acylcarnitine-translocase (CACT) is fundamental for lipid catabolism. To probe the effect of CACT down-expression on lipid metabolism in muscle, human myocytes were stably transfected with CACT-antisense construct. In presence of low concentration of palmitate, transfected cells showed decreased palmitate oxidation and acetyl-carnitine content, increased palmitoyl-carnitine level, and reduced insulin-dependent decrease of fatty acylcarnitine-to-fatty acyl-CoA ratio. The augmented palmitoyl-carnitine synthesis, also in the presence of insulin, could be related to an altered regulation of carnitine-palmitoyl-transferase 1 (CPT 1) by malonyl-CoA, whose synthesis is dependent by the availability of cytosolic acetyl-groups. Indeed, all the described effects were completely overcome by CACT neo-expression by recombinant adenovirus vector or by addition of acetyl-carnitine to cultures. Acetyl-carnitine effect was related to an increase of malonyl-CoA and was abolished by down-expression, via antisense RNA strategy, of acetyl-CoA carboxylase-beta, the mitochondrial membrane enzyme involved in the direct CPT 1 inhibition via malonyl-CoA synthesis. Thus, in our experimental model the modulation of CACT expression has consequences for CPT 1 activity, while the biologic effects of acetyl-carnitine are not associated with a generic supply of energy compounds but to the anaplerotic property of the molecule.

  • Surgical approach to the stylohyoid process in Eagle's syndrome.
    Publication Date: 01/05/2005, on Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons
    by Buono U, Mangone GM, Michelotti A, Longo F, Califano L
    DOI: 10.1016/j.joms.2004.10.013

  • The role of the hinge loop in domain swapping. The special case of bovine seminal ribonuclease.
    Publication Date: 08/04/2005, on The Journal of biological chemistry
    by Picone D, Di Fiore A, Ercole C, Franzese M, Sica F, Tomaselli S, Mazzarella L
    DOI: 10.1074/jbc.M413157200

    Bovine seminal ribonuclease (BS-RNase) is a covalent homodimeric enzyme homologous to pancreatic ribonuclease (RNase A), endowed with a number of special biological functions. It is isolated as an equilibrium mixture of swapped (MxM) and unswapped (M=M) dimers. The interchanged N termini are hinged on the main bodies through the peptide 16-22, which changes conformation in the two isomers. At variance with other proteins, domain swapping in BS-RNase involves two dimers having a similar and highly constrained quaternary association, mainly dictated by two interchain disulfide bonds. This provides the opportunity to study the intrinsic ability to swap as a function of the hinge sequence, without additional effects arising from dissociation or quaternary structure modifications. Two variants, having Pro19 or the whole sequence of the hinge replaced by the corresponding residues of RNase A, show equilibrium and kinetic parameters of the swapping similar to those of the parent protein. In comparison, the x-ray structures of MxM indicate, within a substantial constancy of the quaternary association, a greater mobility of the hinge residues. The relative insensitivity of the swapping tendency to the substitutions in the hinge region, and in particular to the replacement of Pro19 by Ala, contrasts with the results obtained for other swapped proteins and can be rationalized in terms of the unique features of the seminal enzyme. Moreover, the results indirectly lend credit to the hypothesis that the major role of Pro19 resides in directing the assembly of the non-covalent dimer, the species produced by selective reduction of the interchain disulfides and considered responsible for the special biological functions of BS-RNase.

  • Differential expression of multiple transglutaminases in human colon: impaired keratinocyte transglutaminase expression in ulcerative colitis.
    Publication Date: 01/04/2005, on Gut
    by D'Argenio G, Calvani M, Della Valle N, Cosenza V, Di Matteo G, Giorgio P, Margarucci S, Petillo O, Jori FP, Galderisi U, Peluso G
    DOI: 10.1136/gut.2004.049411

    Ulcerative colitis (UC) is characterised by refractory inflammatory ulceration and damage to the colon. The mechanisms underlying impaired healing have yet to be defined. As transglutaminase expression resulting in matrix protein cross linking is associated with increased wound healing in a rat model of colitis, we hypothesised that different types of transglutaminase might also play a role in UC.

  • Methods to improve the yield and quality of DNA from dried and processed figs.
    Publication Date: 01/03/2005, on Biotechnology progress
    by Di Bernardo G, Galderisi U, Cipollaro M, Cascino A
    DOI: 10.1021/bp049710p

    We describe here a molecular method that can be used to detect genome traits of a given horticultural item at each stage from the farm to the market. We developed a procedure to extract and amplify by PCR DNA obtained from complex matrixes, such as dried figs and fig jam. Few fragmented DNA molecules can be recovered from food products. However, we were able to increase the yield of PCR reactions by successfully applying an enzymatic repair protocol to retrieved DNA.

  • Peripheral neuropathy in hepatitis-related mixed cryoglobulinemia: electrophysiologic follow-up study.
    Publication Date: 01/03/2005, on Muscle & nerve
    by Ammendola A, Sampaolo S, Ambrosone L, Ammendola E, Ciccone G, Migliaresi S, Di Iorio G
    DOI: 10.1002/mus.20184

    A retrospective study was performed on 27 patients with hepatitis C (HCV)-related mixed cryoglobulinemia (purpura, arthralgia, hepatitis, glomerulonephritis, peripheral neuropathy) to assess peripheral nerve involvement during follow-up of up to 8 years. All patients had the same degree of organ/system involvement initially and were clinically evaluated at least annually. All 27 patients received steroids; 15 also received recombinant interferon-alpha 2b (rIFN-alpha 2b). At first examination, neurological signs and electrodiagnostic findings consistent with peripheral neuropathy were found in 20 (74%) and in 24 (88.8%) patients, respectively. Neurological evaluation and electrodiagnostic data at 3 and 8 years revealed worsening of neuropathy, whereas the other manifestations of mixed cryoglobulinemia (MC) were stable. At the last examination, clinical and electrodiagnostic signs of neuropathy were found in 25 patients (92.5%), occurring in 1 of 3 patients with normal initial findings, and worsened in 8. A more severe neuropathy was observed in 3 (25%) of the patients treated with prednisone alone and in 6 (40%) of the patients additionally treated with rIFN-alpha 2b. Our data confirm that in patients with HCV-related MC, peripheral nerve involvement is frequent, is progressive, and does not seem to benefit by addition of rIFN-alpha 2b to steroid treatment.

  • Molecular pathways involved in neural in vitro differentiation of marrow stromal stem cells.
    Publication Date: 01/03/2005, on Journal of cellular biochemistry
    by Jori FP, Napolitano MA, Melone MA, Cipollaro M, Cascino A, Altucci L, Peluso G, Giordano A, Galderisi U
    DOI: 10.1002/jcb.20315

    In recent years several reports have claimed to demonstrate trans-differentiation, namely that stem cells have been derived from a given tissue and have differentiated into phenotypes characteristic of different tissues following transplantation or in vitro treatment. For example, the mesenchymal stem cells, also referred to as marrow stromal stem cells (MSCs), present in bone marrow, have been induced to differentiate into neurons. We decided to investigate this phenomenon more in depth by a molecular and morphological follow-up. We analyzed the biochemical pathways that are currently induced to trigger neuron-like commitment and maturation of MSCs. Our studies suggest that: (i) the increase in cAMP, induced to differentiate MSCs, activates the classical PKA pathway and not through the exchange protein directly activated by cAMP (EPAC), a guanine nucleotide exchange factor for the small GTPase Rap1 and Rap2; (ii) MEK-ERK signaling could contribute to neural commitment and differentiation; (iii) CaM KII activity seems dispensable for neuron differentiation. On the contrary, its inhibition could contribute to rescuing differentiating cells from death. Our research also indicates that the currently used in vitro differentiation protocols, while they allow the early steps of neural differentiation to take place, are not able to further sustain this process.

  • Biophysical properties of quadruple helices of modified human telomeric DNA.
    Publication Date: 05/02/2005, on Biopolymers
    by Petraccone L, Erra E, Esposito V, Randazzo A, Galeone A, Barone G, Giancola C
    DOI: 10.1002/bip.20189

    Telomeric DNA of a variety of vertebrates including humans contains the tandem repeat d(TTAGGG)n. The guanine rich strand can fold into four-stranded G-quadruplex structures, which have recently become attractive for biomedical research. Indeed, the aptamers based on the quadruplex motif may prove useful as tools aimed at binding and inhibiting particular proteins, catalyzing various biochemical reactions, or even serving as pharmaceutically active agents. The incorporation of modified bases into oligonucleotides can have profound effects on their folding and may produce useful changes in physical and biological properties of the resulting DNA fragments. In this work, the adenines of the human telomeric repeat oligonucleotide d(TAGGGT) and d(AGGGT) were substituted by 2'-deoxy-8-(propyn-1-yl)adenosine (A-->APr) or by 8-bromodeoxyadenosine (A-->ABr). The biophysical properties of the resulting quadruplex structures were compared with the unmodified quadruplexes. NMR and CD spectra of the studied sequences were characteristic of parallel-stranded, tetramolecular quadruplexes. The analysis of the equilibrium melting curves reveals that the modifications stabilize the quadruplex structure. The results are useful when considering the design of novel aptameric nucleic acids with diverse molecular recognition capabilities that would not be present using native RNA/DNA sequences.

  • Interaction proteomics.
    Publication Date: 01/02/2005, on Bioscience reports
    by Monti M, Orrù S, Pagnozzi D, Pucci P
    DOI: 10.1007/s10540-005-2847-z

    The term proteome is traditionally associated with the identification of a large number of proteins within complex mixtures originating from a given organelle, cell or even organism. Current proteome investigations are basically focused on two major areas, expression proteomics and functional proteomics. Both approaches rely on the fractionation of protein mixtures essentially by two-dimensional polyacrylamide gel electrophoresis (2D-gel) and the identification of individual protein bands by mass spectrometric techniques (2D-MS). Functional proteomics approaches are basically addressing two main targets, the elucidation of the biological function of unknown proteins and the definition of cellular mechanisms at the molecular level. In the cell many processes are governed not only by the relative abundance of proteins but also by rapid and transient regulation of activity, association and localization of proteins and protein complexes. The association of an unknown protein with partners belonging to a specific protein complex involved in a particular process would then be strongly suggestive of its biological function. The identification of interacting proteins in stable complexes in a cellular system is essentially achieved by affinity-based procedures. Different strategies relying on this simple concept have been developed and a brief overview of the main approaches presently used in functional proteomics studies is described.