Latest PUBLICATIONS

  • Histopathological heterogeneity and cytopathological similarity of findings in different muscles of two brothers affected by rigid spine syndrome.
    Publication Date: 01/12/1989, on Journal of the neurological sciences
    by Di Iorio G, Lus G, Cutillo C, Cecio A, Cotrufo R
    DOI:

    The pathological changes in muscles biopsied from 2 brothers with rigid spine syndrome are reported. The findings ranged from marked fascicular atrophy and fibrosis to hypotrophy of small groups of fibres and vacuolation in most fibres. The presence of vacuoles and deposits of accumulated material seemed to be common to all the biopsies. These findings, compared with those reported in the literature, confirmed the histopathological heterogeneity of this syndrome but proposed also the hypothesis that similar elementary lesions of muscle fibres can account for the initiation of the pathological process, developing asynchronously in different muscles because of their different activity.

  • Thyrotropin stimulates transcription from the ferritin heavy chain promoter.
    Publication Date: 30/11/1989, on Biochemical and biophysical research communications
    by Colucci-D'Amato LG, Ursini MV, Colletta G, Cirafici A, de Francisis V
    DOI:

    Thyrotropin (TSH) is the primary hormone regulating the activity of the thyroid gland. We have recently shown that TSH stimulates H-ferritin mRNA levels in rat thyroid. Ferritin plays a key role in determining the intracellular fate of iron. The induction of ferritin synthesis by iron in liver is regulated both at transcriptional and translational levels. Here we present evidence that the mechanisms by which TSH regulates the mRNA levels are mediated by a diffusible product acting in trans on its own promoter. In fact, the H-ferritin promoter mediates increased CAT activity in response to hormone induction. Our results identify transcription as an important regulatory step of TSH action. They suggest that TSH induces expression of the ferritin gene, and that continuous protein synthesis is required to maintain basal ferritin gene expression in the absence of hormone.

  • Memory encoding processes in mild and severe dementia. Preliminary data.
    Publication Date: 01/10/1989, on Functional neurology
    by Chiacchio L, Trojano L, Orsini A, Grossi D
    DOI:

    Memory coding processes can be divided according to their attentional requirement into "automatic" and "effortful". The aim of current research was to explore both automatic and effortful processes in early and late stages of Alzheimer type dementia. Patients were classified on the basis of restrictive clinical and neuropsychological criteria, in order to pinpoint possible specific impairments in the two patients' subgroups. The present paper reports preliminary data about 15 mildly and 15 severely demented patients. Statistical analysis showed that both the automatic and the effortful coding processes are impaired at the late but also at the early stages of dementia.

  • On the different roles of the cerebral hemispheres in mental imagery: the "o'Clock Test" in two clinical cases.
    Publication Date: 01/05/1989, on Brain and cognition
    by Grossi D, Modafferi A, Pelosi L, Trojano L
    DOI:

    This paper develops the hypothesis of different roles of the two hemispheres in imaginal processes. A test designated the "o'Clock Test" is proposed, which contains closely confrontable perceptual and imaginal tasks. It enables examination of the abilities both to generate mental images and to explore them in their right and left halves (R + L Condition). This test was used to examine two patients, one severely affected by hemi-inattention resulting from a right posterior lesion, and the other with a selective deficit of imagery due to a left occipital lesion. The former demonstrated left neglect in both perceptive and imaginal capacities, while the latter was able to perform correctly only the perceptive tasks. These results suggest that the right hemisphere has functions of organization and spatial exploration at both perceptive and imaginal levels, and that the left hemisphere's role is to generate mental images.

  • Normalization of short-chain acylcoenzyme A dehydrogenase after riboflavin treatment in a girl with multiple acylcoenzyme A dehydrogenase-deficient myopathy.
    Publication Date: 01/05/1989, on Annals of neurology
    by DiDonato S, Gellera C, Peluchetti D, Uziel G, Antonelli A, Lus G, Rimoldi M
    DOI: 10.1002/ana.410250510

    A 12-year-old girl was shown to have carnitine-deficient lipid storage myopathy and organic aciduria compatible with multiple acylcoenzyme A (acyl-CoA) dehydrogenase deficiency. In muscle mitochondria, activities of both short-chain acyl-CoA dehydrogenase (SCAD) and medium-chain acyl-CoA dehydrogenase (MCAD) were 35% of normal. Antibodies against purified SCAD, MCAD, and electron-transfer flavoprotein were used for detection of cross-reacting material (CRM) in the patient's mitochondria. Western blot analysis showed absence of SCAD-CRM, reduced amounts of MCAD-CRM, and normal amounts of electron-transfer flavoprotein-CRM. The patient, who was unresponsive to treatment with oral carnitine, improved dramatically with daily administration of 100 mg oral riboflavin. Increase in muscle bulk and strength and resolution of the organic aciduria were associated with normalization of SCAD activity and "reappearance" of SCAD-CRM. In contrast, both MCAD activity and MCAD-CRM remained lower than normal. These results suggest that in some patients with multiple acyl-CoA dehydrogenase deficiency riboflavin supplementation may be effective in restoring the activity of SCAD, and possibly of other mitochondrial flavin-dependent enzymes.

  • Conformational properties of deltorphin: new features of the delta-opioid receptor.
    Publication Date: 24/04/1989, on FEBS letters
    by Temussi PA, Picone D, Tancredi T, Tomatis R, Salvadori S, Marastoni M, Balboni G
    DOI:

    Deltorphin is an opioid peptide with the sequence H-Tyr-D-Met-Phe-His-Leu-Met-Asp-NH2, recently isolated from the skin of Phyllomedusa sauvagei. Its enormous selectivity towards the delta-opioid receptor and the similarity of the N-terminal part of the sequence with that of dermorphin (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2), a mu selective peptide isolated from the same natural source, prompted a comparative conformational study. A 1H-NMR study in two different solvent systems showed that the conformational preferences of the N-terminal sequences of the two peptides are similar. The different selectivities towards opioid receptors have been interpreted in terms of charge effects. Besides a general trend consistent with the role of the membrane in the preselection of the peptides, the present study demonstrates the crucial role played by charged residues in the interaction inside the receptors.

  • Conformational analysis of peptide T and of its C-pentapeptide fragment.
    Publication Date: 01/01/1989, on Biopolymers
    by Motta A, Picone D, Temussi PA, Marastoni M, Tomatis R
    DOI: 10.1002/bip.360280142

    The synthetic peptide of sequence H-Ala-Ser-Thr-Thr-Thr-Asn-Tyr-Thr-OH, termed peptide T, a competitor of the Human Immunodeficiency Virus in the binding to human T cells, and its C-terminal pentapeptide fragment, were studied by 1H-nmr in DMSO solution to determine conformational preferences. The observation of nuclear Overhauser enhancements (NOEs) for both peptides, and unusual finding for small linear peptides, allowed complete sequence-specific resonance assignments. Long-range NOEs, ring-current shifts, and the very small temperature coefficient of the Thr8 NH chemical shift suggest, for the zwitterionic form of peptide T, the presence in solution of a beta-turn involving Thr5, Asn6, Tyr7 and Thr8. This conformational feature is consistent with previous structure-activity relationship studies indicating the invariance of the same residues in several potent pentapeptide analogues. The studied pentapeptide fragment, although less structured, shows some tendency to fold even in a polar solvent such as DMSO. Preliminary chemotaxis data on some pentapeptide analogues are consistent with our structural model.

  • Bioactive conformation of linear peptides in solution: an elusive goal?
    Publication Date: 01/01/1989, on Biopolymers
    by Temussi PA, Picone D, Castiglione-Morelli MA, Motta A, Tancredi T
    DOI: 10.1002/bip.360280112

    Bioactive peptides of natural origin have, in general, short linear sequences, and are characterized by a large conformational flexibility. It is very difficult to study their conformation in solution since they exist, almost invariably, as a complex mixture of numerous conformers, most of which are extended. The so-called bioactive conformation may be one of them, although the solvents used in solution studies often have properties drastically different from those of the biological system in which the peptide acts. There is, however, no simple way of identifying the bioactive conformation amid the many existing conformers. It is possible to approach a solution to this problem using two distinct strategies: (a) Limiting the conformational freedom of the peptide, e.g., by increasing the viscosity of the solution and decreasing the temperature, in the assumption that the bioactive conformation is, even slightly, more stable than the others. (b) Trying to mimic in solution the physicochemical features of the more reliable receptor models. These two approaches will be illustrated with examples taken mainly from opioid peptides.

  • Enzymatic methyl esterification of synthetic tripeptides: structural requirements of the peptide substrate. Detection of the reaction products by fast-atom-bombardment mass spectrometry.
    Publication Date: 15/10/1988, on European journal of biochemistry
    by Galletti P, Ingrosso D, Manna C, Sica F, Capasso S, Pucci P, Marino G
    DOI:

    Eukaryotic protein carboxyl methyltransferase catalyzes a two-substrates reaction in which the methyl group of S-adenosylmethionine is transferred to the free carboxyl group of D-aspartyl and L-isoaspartyl-containing peptide or protein substrates. It has been previously shown that at least three binding sites are required for the interaction of adenosylmethionine with the enzyme and/or the protein substrate [Oliva A., Galletti P., Zappia V., Paik W. K. & Kim S. (1980) Eur. J. Biochem. 104, 595-602], while very little is known concerning the structural requirements of the protein substrate. In this study several synthetic tripeptides were selected in order to elucidate the structural requirements of the methyl-accepting substrates. The results obtained with this series of peptides suggested that: (1) three residues appear to be the minimal length, so far identified, required for a productive enzyme-substrate interaction, several dipeptides being ineffective as substrates [McFadden P. N. & Clarke S. (1986) J. Biol. Chem. 261, 11,503-11,511]; (2) the isoaspartyl residue is not recognized unless its alpha-amino group is involved in a carboamide bond; (3) an hydrogen atom on the amide linkage following the isoaspartyl residue is essential for both recognition and catalysis; (4) oligopeptides containing both D-aspartyl and D-isoaspartyl residues are not recognized by this methyltransferase. On the basis of these results, interaction sites between the peptide substrate and the enzyme molecule have been proposed. This paper also reports the first application of fast-atom-bombardment mass spectrometry to the detection of the products of the enzymatic methyl esterification reaction. By this soft ionization technique, the methyl-esterified peptides as well as the corresponding cyclic imides generated during the spontaneous demethylation process have been identified.

  • Selective "semantic amnesia" after closed-head injury. A case report.
    Publication Date: 01/09/1988, on Cortex; a journal devoted to the study of the nervous system and behavior
    by Grossi D, Trojano L, Grasso A, Orsini A
    DOI:

    An 18-year-old girl with a left parietal lesion caused by a closed-head injury exhibited a peculiar memory impairment. The patient showed selective "semantic amnesia" (severe loss of the stock of notions acquired prior to the disease), while autobiographic memory and spatial learning ability were preserved. The semantic/episodic distinction is discussed in the light of the patient's performance on neuropsychological tasks.

  • Immediate memory spans in dementia.
    Publication Date: 01/08/1988, on Perceptual and motor skills
    by Orsini A, Trojano L, Chiacchio L, Grossi D
    DOI: 10.2466/pms.1988.67.1.267

    Spatial span (Corsi's block-tapping test) and verbal spans for digits (Wechsler Digits Forward Test) and for words were measured in 30 normal subjects and in 51 demented patients, divided into two groups (mildly demented and severely demented) according to selective clinical and neuropsychological criteria. Statistical analysis showed significant differences among the three groups for spatial span. By contrast, controls' and mildly demented patients' performances on both verbal spans were not significantly different. These findings are discussed in the light of theory about working memory.

  • Seasonal fluctuations in plasma progesterone concentrations in Gentile-di-Puglia and Ile-de-France ewes in southern Italy.
    Publication Date: 01/07/1988, on Journal of reproduction and fertility
    by Dell'Aquila S, Varriale B, Alberico G, Pierantoni R
    DOI:

    Ile-de-France ewes had high plasma progesterone concentrations during early summer-late winter. Gentile-di-Puglia ewes had high progesterone values during the winter-spring-summer period but during autumn progesterone values were very low and oestrous behaviour was not displayed. The comparison with Ile-de-France ewes indicates that a phase shift occurs in the annual ovarian activity in ewes of the Gentile-di-Puglia breed.

  • A 500 MHz study of peptide T in a DMSO solution.
    Publication Date: 11/04/1988, on FEBS letters
    by Picone D, Temussi PA, Marastoni M, Tomatis R, Motta A
    DOI:

    Peptide T, an octapeptide of sequence ASTTTNYT that binds to human T cells, was studied as a zwitterion in DMSOd6 solution by means of proton NMR spectroscopy at 500 MHz. The unusual dispersion of the resonances of residues of the same type (T) makes it possible to assign all resonances to specific residues by means of several 2D techniques. The non-random nature of the conformation is substantiated by the observation of sequential nuclear Overhauser enhancements (NOEs). The low value of the temperature coefficient of the chemical shift of the NH of T8 and a diagnostic NOE between the NHs of T7 and T8 hint that a beta-turn including T5, N6, Y7 and T8 is a prominent conformational feature in solution. The ring current high field shifts of the methyl group and of the NH of T8 are consistent with an interaction with the side-chain of Y7, favoured by the beta-turn.

  • Hypothalamus-hypophysis and testicular GnRH control of gonadal activity in the frog, Rana esculenta: seasonal GnRH profiles and annual variations of in vitro androgen output by pituitary-stimulated testes.
    Publication Date: 01/04/1988, on General and comparative endocrinology
    by Fasano S, Minucci S, Pierantoni R, Fasolo A, Di Matteo L, Basile C, Varriale B, Chieffi G
    DOI:

    The binding of a gonadotrophin-releasing hormone (GnRH) long acting analog (GnRHA), D-Ser (But)6,Pro9-NEt GnRH (HOE 766), to pituitary and testicular extracts and the presence of GnRH-like material in testes and hypothalamuses were measured in the frog, Rana esculenta. Also, the cellular localization of immunoreactive GnRH was investigated in testes by immunohistochemical staining. Furthermore, lyophilized preparations of pituitary crude homogenates from animals caught monthly were tested in vitro for their ability to stimulate androgen production by December testes. Satisfactory results on specific 125I-GnRH binding were difficult to obtain in view of its low binding capacity. Moreover, binding in testicular homogenates was of the same order of magnitude (about 2%) as that found in pituitaries. In a cospecific radioimmunoassay for GnRH nonapeptide, both hypothalamic and testicular extracts gave displacement parallel to the standard curve. Immunoreactive GnRH did not significantly fluctuate in hypothalamuses, while it peaked in testes during December and July. Immunoreactive GnRH was evidenced in June and September testes employing immunohistochemical staining. In particular, the interstitial cells and the Sertoli cells were faintly stained. Testes of December animals stimulated by February pituitaries produced larger quantities of androgens as compared with testes stimulated with hypophyseal preparations from the remaining periods of the year. In conclusion, the present results are consistent with the idea that seasonal changes of the hypothalamus-hypophyseal activity play an important role in regulating the hormonal response in vertebrate testes. Moreover, we report that, in addition to rats, GnRH-like material is present in frog testes and for the first time it has been shown that such putative intratesticular material undergoes seasonal fluctuations in a vertebrate.

  • Relationship between estradiol-17 beta seasonal profile and annual vitellogenin content of liver, fat body, plasma, and ovary in the frog (Rana esculenta).
    Publication Date: 01/03/1988, on General and comparative endocrinology
    by Varriale B, Pierantoni R, Di Matteo L, Minucci S, Milone M, Chieffi G
    DOI:

    The seasonal plasma estradiol-17 beta (E2-17 beta) profile and annual vitellogenin content of liver, fat body, plasma, and ovary were investigated in Rana esculenta. Concomitant with the increase in E2-17 beta, vitellogenin peaked in liver, plasma, and ovary during autumn and winter, while it remained at a relatively high concentration in fat body during spring. In vitro experiments showed that E2-17 beta (10(-9) M) is ineffective in inducing vitellogenin production in fat body, but is effective in inducing vitellogenin production in liver. As fat bodies do not produce the vitellogenin they contain, we suggest that fat bodies are involved in the transfer of vitellogenin to the ovary.