Novel 3-beta-methoxysteroids from the Senegalese sponge Microscleroderma spirophora.
Publication Date: 01/03/1994, on Steroids
by Costantino V, Fattorusso E, Mangoni A, Aknin M, Gaydou EM
The Senegalese sponge Microscleroderma spirophora has been found to produce exclusively very unusual 3 beta-methoxysteroids in place of the common 3 beta-hydroxysteroids. Six different methoxysteroids (three of which are novel compounds) have been isolated and identified by spectroscopic means (MS, IR, 1H and 13C NMR), and their taxonomic significance discussed. A new method for the determination of the configuration at C-24 in saturated 24-ethyl side chains is also proposed.
A critical review of mental imagery defects.
Publication Date: 01/03/1994, on Brain and cognition
by Trojano L, Grossi D
A critical, clinical review of single-case reports and group studies on visual mental imagery deficits is offered. Neuropsychological findings demonstrate that mental imagery relies upon dissociable processes which are localized in left-hemisphere posterior areas. Imagery defects thus may often be associated with visual recognition and naming impairments. On the other hand, the right hemisphere seems to play an analogous role in imagery and perception. Current theoretical models of imagery do not appear fully capable of accounting for available clinical data.
Selective opioid dipeptides.
Publication Date: 15/02/1994, on Biochemical and biophysical research communications
by Temussi PA, Salvadori S, Amodeo P, Bianchi C, Guerrini R, Tomatis R, Lazarus LH, Picone D, Tancredi T
The surprising change of selectivity induced by the change of chirality in peptides containing the tetrahydro-3-isoquinoline carboxylic acid (Tic) in second position, interpreted as a conformational preference induced on the Tyr-Xaa-Phe domain, can instead be attributed to the Tyr-Tic message domain. The relative spatial disposition of the aromatic ring of delta-selective non peptidic opiates is compatible with a message domain, in opioid peptides, of only two residues. This hypothesis was tested through the synthesis of Tyr-L-Tic-NH2, Tyr-D-Tic-NH2, Tyr-L-Tic-Ala-NH2, Tyr-L-Tic-Ala-OH and Tyr-D-Tic-Ala-NH2. Peptides containing Tyr-L-Tic- behave as very selective delta antagonists and those containing Tyr-DTic- as non selective agonists. This is the first case of opioid peptides containing a two-residue message domain and of opioid dipeptides with substantial opioid activity.
c-fos spontaneous expression during wakefulness is reversed during sleep in neuronal subsets of the rat cortex.
Publication Date: 01/01/1994, on Journal of physiology, Paris
by Grassi-Zucconi G, Giuditta A, Mandile P, Chen S, Vescia S, Bentivoglio M
Neurofilament proteins are synthesized in nerve endings from squid brain.
Publication Date: 01/09/1993, on Journal of neurochemistry
by Crispino M, Capano CP, Kaplan BB, Giuditta A
It is generally believed that the proteins of the nerve endings are synthesized on perikaryal polysomes and are eventually delivered to the presynaptic domain by axoplasmic flow. At variance with this view, we have reported previously that a synaptosomal fraction from squid brain actively synthesizes proteins whose electrophoretic profile differs substantially from that of the proteins made in nerve cell bodies, axons, or glial cells, i.e., by the possible contaminants of the synaptosomal fraction. Using western analyses and immunoabsorption methods, we report now that (a) the translation products of the squid synaptosomal fraction include neurofilament (NF) proteins and (b) the electrophoretic pattern of the synaptosomal newly synthesized NF proteins is drastically different from that of the NF proteins synthesized by nerve cell bodies. The latter results exclude the possibility that NF proteins synthesized by the synaptosomal fraction originate in fragments of nerve cell bodies possibly contaminating the synaptosomal fraction. They rather indicate that in squid brain, nerve terminals synthesize NF proteins.
Protein synthesis in a synaptosomal fraction from squid brain.
Publication Date: 01/08/1993, on Molecular and cellular neurosciences
by Crispino M, Castigli E, Perrone Capano C, Martin R, Menichini E, Kaplan BB, Giuditta A
A synaptosomal fraction from squid brain containing a large proportion of well-presarved nerve terminals displays a high rate of [(35)S]methionine incorporation into protein. The reaction is dependent on time and protein concentration, is strongly inhibited by hypo-osmotic shock and cycloheximide, and is not affected by RNase. Chloramphenicol, an inhibitor of mitochondrial protein synthesis, partially inhibits the reaction. The ionic composition of the incubation medium markedly modulates the rate of [(35)S]methionine incorporation. Na(+) and K(+) ions are required for maximal activity, while complete inhibition is achieved by addition of the calcium ionophore A23187 and, to a substantial extent, by tetraethylammonium, ouabain, and high concentrations K(+). A thermostable inhibitor of synaptosomal protein synthesis is also present in the soluble fraction of squid brain. Using sucrose density gradient sedimentation procedures, cytoplasmic polysomes associated with nascent radiolabeled peptide chains have been identified in the synaptosomal preparation. Newly synthesized synaptosomal proteins are largely associated with a readily sedimented particulate fraction and may be resolved by gel electrophoresis into more than 30 discrete bands ranging in size from about 14 to 200 kDa. The electrophoretic pattern of the newly synthesized synaptosomal proteins is significantly different from the corresponding patterns displayed by the giant axon's axoplasm and by glial and nerve cell bodies (in the stellate nerve and ganglion, respectively). On the whole, these observations suggest that the nerve endings from squid brain are capable of protein synthesis.
The effects of gonadectomy and testosterone treatment on the Harderian gland of the green frog, Rana esculenta.
Publication Date: 01/08/1993, on Cell and tissue research
by Chieffi-Baccari G, D'Matteo L, d'Istria M, Minucci S, Serino I, Varriale B
The effects of gonadectomy and testosterone treatment on the fine structure of the Harderian gland in male and female green frogs were investigated in different periods of the year. Gonadectomy, carried out when the glands are in the lowest secretory phase (September), causes degenerative changes consisting of a reduction of the rough endoplasmic reticulum, the appearance of autolysosomes, and an increase of nuclear heterochromatin. These effects can be prevented by testosterone treatment. No castration effects are found during the recovery (November) and enhancement (April-May) phases of secretory activity. The results suggest that the frog Harderian gland's sensitivity to testosterone changes during the annual cycle. The androgen dependence of the Harderian gland is correlated with the presence of androgen receptors in both male and female frogs.
Familial amyloidotic polyneuropathy: description of an Italian kindred.
Publication Date: 01/05/1993, on Italian journal of neurological sciences
by Di Iorio G, Sanges G, Cerracchio A, Sampaolo S, Sannino V, Bonavita V
Familial amyloidotic polyneuropathy (FAP) is a heterogeneous group of genetic disorders characterized by progressive systemic deposition of extracellular amyloid fibrils, mainly affecting the peripheral nervous system (PNS). These disorders, inherited as an autosomal dominant trait, have frequently been described in various ethnic groups, but have rarely been reported in Italy. A 42 year-old man came to our observation for loss of pain and temperature sense in his legs. Clinical and laboratory data pointed to an amyloidotic polyneuropathy. This led us to discover a large italian kindred in which 19 members were affected by FAP. The diagnosis, established in 8 members on the clinical and laboratory findings, was ana-catamnestic in other 11. In this kindred the onset of the disease ranges from 35 to 50 years of age and the course is progressive and often fatal. The early symptoms are mainly related to autonomic disturbances and to peripheral neuropathy. Cardiac and renal involvement occurs frequently and may be life-threatening.
Solution structure of casokefamide.
Publication Date: 31/03/1993, on Biochemical and biophysical research communications
by Brantl V, Picone D, Amodeo P, Temussi PA
Casokefamide (Tyr-D-Ala-Phe-D-Ala-Tyr-NH2) is a synthetic peptide derived from the beta-casomorphin sequence, designed to increase the resistance to gastric proteases. Casokefamide binds to both mu and delta-opioid receptors, while beta-casomorphins and its fragments are typical mu-opioid receptor agonists. Furthermore, casokefamide can affect gastric acid and pancreatic exocrine secretions and also gastrointestinal motility. We have undertaken a conformational study on this peptide based on NMR measurements in a DMSOd6/H2O cryomixture at 265 K and energy calculations. The predominant conformation is characterised by the absence of regular structures and intramolecular hydrogen bonds. The conformation of the message domain is reminiscent of the shape of several peptidic and non peptidic opiates, with the D-Ala2CH3 group sandwiched between Tyr1 and Phe3 aromatic rings.
Slowly progressive aphasia associated with surface dyslexia.
Publication Date: 01/03/1993, on Cortex; a journal devoted to the study of the nervous system and behavior
by Chiacchio L, Grossi D, Stanzione M, Trojano L
We report an Italian patient affected by slowly progressive aphasia (SPA) lasting since four years when he first came to our observation. During the successive four years, we documented a progressive language decline resembling transcortical sensory aphasia, associated with a reading disorder corresponding to surface dyslexia, a form extremely rare in patients with native transparent language. His performance at standard intelligence tasks remained in the normal range, without any variation. CT scan showed left temporal atrophy. We emphasize the heterogeneity of the syndrome of SPA and suggest that it can represent one of the pictures of focal cortical degenerative disease, with variable onset, progression, and evolution.
Solution conformation of CCK9, a cholecystokinin analog.
Publication Date: 15/02/1993, on Biochemical and biophysical research communications
by Moroder L, D'Ursi A, Picone D, Amodeo P, Temussi PA
Cholecystokinin (CCK) is a peptide hormone endowed with several important biological activities, both in the central and peripheral nervous system. Previous conformational studies have dealt mainly with its C-terminal octapeptide fragment (CCK8), which represents the shortest fully circulating form of this hormone. We have undertaken a detailed NMR conformational study in a DMSOd6/H2O cryomixture at 278 K of the CCK analog H-Arg-Asp-Tyr(SO3H)-Thr-Gly-Trp-Nle-Asp-PheNH2 (CCK9) which retains all the bioactivities of CCK8, but was found to be remarkably more stable in acidic media and unaffected by air oxidation due to Met replacements. The predominant conformation contains a gamma-turn centered on Thr4, separated by Gly5 from a helical segment that comprises the C-terminal residues.
Memory for visuospatial patterns in Alzheimer's disease.
Publication Date: 01/02/1993, on Psychological medicine
by Grossi D, Becker JT, Smith C, Trojano L
Immediate memory for visuospatial information was assessed in patients affected by Alzheimer-type dementia but with unimpaired visuo-perceptual functions. Patients were given two tasks: one was a traditional visuospatial memory task (Corsi's block tapping test), the second explored specifically immediate memory for visuospatial patterns. The experiment was conducted in two parallel groups of patients in Italy and the United States, each with its own appropriate sample of normal control subjects. Results showed a specific deficit of visual working memory in demented patients, even in a task in which control subjects achieved error-free performance. These data are interpreted in the light of the Working Memory Model, and suggest that in dementia the functions of the Visuospatial Scratchpad, unlike the functions of the verbal subsystems, may be impaired.
Copying procedures in focal brain-damaged patients.
Publication Date: 01/01/1993, on Italian journal of neurological sciences
by Trojano L, De Cicco G, Grossi D
We aimed to ascertain whether non-apraxic, focal brain-damaged patients used abnormal constructional procedures. We tested a series of consecutive patients, classified according to lesion locus and side against a matched sample of normal volunteers. Subjects had to copy the Rey-Osterreith Figure, a complex and structured item that explores copying strategies. We used special testing and scoring methods to analyze different steps of the copy. Unlike the controls, the patients did not choose the central elements of the figure as guiding structures. All patient groups followed an equivalent "pathological", "piecemeal" procedure.
Long-term habituation to spatial novelty modifies posttrial synchronized sleep in rats.
Publication Date: 01/01/1993, on Brain research bulletin
by Montagnese P, Mandile P, Vescia S, Sadile AG, Giuditta A
To assess the role of posttrial synchronized sleep in the processing of a nonassociative task, adult male Sprague-Dawley rats with chronically implanted cortical electrodes for EEG recording were exposed to a Làt-maze, and horizontal (HA; corner crossing) and vertical (VA; rearings) activities were monitored during two 10-min test trials made at a 3-h (experiment 1) or 24-h (experiment 2) interval. EEG conventional recording was taken during 3 h under baseline conditions (day 1), and following exposure to the maze (day 2), and analyzed as to the amount (a), number (n), and mean duration (d) of synchronized sleep (SS) episodes followed by wakefulness (SS-->W) or by paradoxical sleep (SS-->PS). In both experiments there was a significant intertrial decrement (long-term habituation: LTH) for horizontal activity (LTH-HA), vertical activity (LTH-VA), and emotionality (LTH-E). In experiment 1, in comparison to baseline values, the posttrial SS-->PS(a) increased, mainly for the appearance of SS-->PS episodes in the 1st h. SS-->W(a) also increased in the first h. Correlative analyses among behavioral and sleep parameters showed that SS-->PS(n) and (d) covaried positively with LTH-HA relative to the entire test, and with LTH-VA relative to the second part of the test in the third h. Negative correlations were present between SS-->PS(n) and (d), and LTH-E. In experiment 2, exposed rats showed a lower SS-->PS(n) in the first hour and an increased SS-->PS(d) in the second hour. No change was observed as to SS-->W episodes.(ABSTRACT TRUNCATED AT 250 WORDS)
Impaired drawing from memory in a visual agnosic patient.
Publication Date: 01/11/1992, on Brain and cognition
by Trojano L, Grossi D
A case is reported of an associative visual agnosic patient who could not draw from memory objects he could recognize, even though he could copy drawings flawlessly. His ability to generate mental visual images was found to be spared, as was his ability to operate upon mental images. These data suggest that the patient could generate mental images but could not draw from memory because he did not have access to stored knowledge about pictorial attributes of objects. A similar functional impairment can be found in some other visual agnosic patients and in patients affected by optic aphasia. The present case allows a discussion of relationships among drawing from memory, imagery, and copying procedures.