Search Results - (Author, Cooperation:M. Rizzi)

2018-03-28

The American Society for Microbiology (ASM)

0066-4804

1098-6596

Biology

Medicine

2018-09-01

Institute of Physics Publishing (IOP)

1748-0221

Physics

2012-04-24

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; GTP-Binding Protein alpha Subunits/deficiency/genetics ; Light ; Maze Learning ; Mice ; Retinal Bipolar Cells/ultrastructure ; Retinal Horizontal Cells/ultrastructure ; Retinal Rod Photoreceptor Cells/cytology/*physiology/radiation ; effects/*transplantation ; Transducin/deficiency/genetics ; Vision, Ocular/*physiology/radiation effects ; Visual Cortex/physiology/radiation effects

2018-04-26

The Company of Biologists

0950-1991

1477-9129

Biology

Cardiovascular development and regeneration, Neural development

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract: Intracerebral microdialysis combined with a sensitive and specific radioimmunoassay was used to monitor the neuronal release of somatostatin (somatostatin-like immunoreactivity, SLI) in the dorsal hippocampus of freely moving rats. The sensitivity of the radioimmunoassay was optimized to detect 〈1 fmol/ml. The basal concentration of SLI in 20-min dialysate fractions (5 μl/min) collected 24 h after probe implantation was stable over at least 200 min. The spontaneous efflux dropped by 54 ± 6.4% (p 〈 0.05) when Ca2+ was omitted and 1 mM EGTA added to the Krebs-Ringer solution and by 65.5 ± 3.2% (p 〈 0.05) in the presence of 1 μM tetrodotoxin. Depolarizing concentrations of the Na+ channel opener veratridine (6.25, 25, 100 μM) induced 11 ± 2 (p 〈 0.05), 17 ± 2 (p 〈 0.05), and 21 ± 5 (p 〈 0.01) fold increase in SLI concentration, respectively, during the first 20 min of perfusion. The effect of 100 μM veratridine was blocked by coperfusion with 5 μM tetrodotoxin (p 〈 0.01) and reduced by 79% (p 〈 0.01) in the virtual absence of Ca2+. Neuronal depolarization by 20 min of perfusion with Krebs-Ringer solution containing 25 and 50 mM KCl and proportionally lowered Na+ increased the dialysate SLI 4.4 ± 1 (p 〈 0.05) and 17 ± 3 (p 〈 0.01) fold baseline, respectively. Ten micromolar ouabain, a blocker of Na+,K+-ATPase, increased the dialysate SLI 15-fold baseline, on average (p 〈 0.05), during 80 min of perfusion. The results demonstrate the suitability of brain microdialysis for monitoring the neuronal release of SLI and for studying its role in synaptic transmission.

Electronic Resource

1460-9568

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

We studied ionotropic glutamate receptor subtypes and the effect of chronic treatment with NBQX [6-nitro-7-sulphamoyl-benzo(F)quinoxaline-2,3-dione], a selective ( rs)-α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor antagonist, in the spinal cord of mnd mice. NBQX (8 mg/kg daily i.p. for 3 weeks starting from 24 weeks old) significantly improved the behavioural scores (hind leg extension reflex, cage rung grasping and gait) in mnd mice, measured after the last drug injection, and increased the number of mice with ‘normal’ gait (from 50% to 90%, P 〈 0.05).Receptor binding autoradiography of the competitive N-methyl- d-aspartate (NMDA) antagonist, [3H]CGP 39653, of [3H]AMPA and [3H]kainic acid in spinal cord sections, measured after 1 week of drug washout, were not significantly different in control and mnd mice, and were not modified by NBQX.GluR2/3 immunoreactivity, assessed using Western blotting, was significantly enhanced (by 59%, P 〈 0.01) in the spinal cord but not in the brain of 28-week-old mnd mice compared to age-matched control mice. NBQX treatment increased GluR2/3 immunoreactivity in the spinal cord of control mice and mnd mice by 327 ± 74% (P 〈 0.01) and 212 ± 52% (P 〈 0.01), respectively.The changes in GluR2/3 subunits may involve adaptive mechanisms of the receptor and play some role in the protective effect of NBQX. These findings suggest that selective antagonism of ionotropic non-NMDA receptors may be of value in the treatment of motor neuron disease.

Electronic Resource

1460-9568

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The release of neuropeptide Y (NPY) was measured from hippocampal slices of rats at stage 2 (preconvulsive stage) and stage 5 (full seizure expression) of electrical kindling of the dorsal hippocampus (upper blade of the dentate gyrus). Spontaneous release in naive rats (9.0 ± 0.8 fmol/ml every 10 min) was independent of external Ca2+ but was reduced by 38 ± 3.6% (P 〈 0.05) during 20 min incubation with 5μM tetrodotoxin. Spontaneous efflux in naive rats did not differ from that in shams (implanted with electrodes but not stimulated) or in rats kindled to stage 2 and stage 5. Twenty-five, 50 and 100 mM KCl induced a concentration-dependent release of NPY (P 〈 0.05 and P 〈 0.01 at 25 and 50–100 mM respectively) from slices of shams. The effect of 100 mM KCl was reduced by 94 ± 1% (P 〈 0.01) in the absence of Ca2+. Two days after the last stage 2 stimulation and 1 week after the last stage 5 seizure, NPY release was significantly larger than in shams at all KCl concentrations in the stimulated and contralateral hippocampus (P 〈 0.05 and P 〈 0.01). Forty-eight hours after one single after-discharge and 1 month after the last stage 5 seizure, 50 mM KCl induced a significantly larger release of NPY in the stimulated and contralateral hippocampus (P 〈 0.01 and P 〈 0.05), although the effect was less than during kindling. The tissue concentration of NPY increased significantly in both hippocampi at stage 2 and 1 week after stage 5 (2.6 times on average, P 〈 0.01) but no significant differences were found 1 month after stage 5. The present results provide the first evidence of enhanced neuronal release of NPY during kindling, suggesting that this neuropeptide may have a potential role in epileptogenesis.

Electronic Resource

1460-9568

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

In this study we examined whether the potency of quinolinic acid (Quin) in inducing neurodegeneration in vivo was dependent on the exposure time of the tissue to the excitotoxin. The effect of chronic infusion of Quin into rat striatum and hippocampus was examined at the light microscopic level and by cell count on 40 μm Cresyl violet stained brain sections. Continuous infusion was at a constant speed (0.5 μl/h) for various times (15 h–2 weeks) by osmotic minipumps (Alzet 2002). No build up of [3H]Quin occurred in the tissue during infusion; this was assessed by measuring the radioactivity 3–14 days after minipump placement. Intrastriatal infusion of 6 and 10 nmol/h Quin, but not of nicotinic acid, for 1 week induced a dose-dependent neurodegeneration (70 and 90% loss of neurons, respectively, compared to the contralateral striatum) extending 1.2–2 mm from the centre of the injection. The onset of the neurotoxicity caused by 10 nmol/h Quin was 〉24 h. One week's infusion of 4 nmol/h Quin did not induce neurotoxicity, but a 40% drop of neurons, compared to the contralateral side, occurred after 2 weeks. One week's intrahippocampal infusion of 2.4 and 6 nmol/h Quin, but not of nicotinic acid, caused a dose-dependent neurodegeneration with a radius of ∼1–1.5 mm around the injection track. The onset of the neurotoxicity induced by 2.4 nmol/h Quin was 〈15 h. The pattern of nerve cell loss induced by 1.2 nmol/h Quin after 1 week (CA4 cells lost in 50% of the rats) did not differ from that observed after 2 weeks of infusion. Nerve cell loss caused by Quin in the striatum and in the hippocampus was restricted to the injected area and antagonized by coinfusion with d(–)-2-amino-7-phosphonoheptanoic and kynurenic acids in molar ratios of 1:0.1 and 1:3, respectively. These data show that Quin's potency in inducing neurodegeneration in the striatum, but not in the hippocampus, depends on the exposure time of the tissue to the excitotoxin. In addition, neurodegeneration is induced faster by Quin in the hippocampus than in the striatum. The usefulness of this model to study the sequelae of the neurotoxic process in vivo will be discussed.

Electronic Resource

0003-2697

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Electronic Resource

0001-9593

Linguistics and Literary Studies

History

0001-9593

Linguistics and Literary Studies

History

Annunzi bibliografici

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0022-2836

crystal structure ; heme protein ; monomeric molluse hemoglobin ; oxygen carrier ; sulfide carrier

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Electronic Resource

0022-2836

X-ray diffraction ; crystallization ; retinol-binding protein ; transthyretin

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Electronic Resource

0022-2836

X-ray crystal structure ; ferric Aplysia limacina myoglobin derivatives (ligand-free, fluoride, ; hemoprotein

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Electronic Resource

0277-5387

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0014-5793

Ligand binding ; Mb, myoglobin ; Myoglobin mutant ; NMR, nuclear magnetic resonance ; Protein engineering ; R"s"y"m". merging R-factor between symmetry related reflections: where I"h ; V mutant, HiS^6^4(E7)-〉Val sperm whale myoglobin single mutant ; VR mutant, HiS^6^4(E7)-〉Val,Thr^6^7(E10)-〉Arg sperm whale myoglobin double ; rms, root mean square

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

1420-911X

Springer Online Journal Archives 1860-2000

Medicine

Résumé L'examen de la posture normale ainsi que de ses variations possibles demande des connaissances approfondies des structures du système locomoteur. C'est ainsi qu'on peut reconnaître les forces actives déterminantes dans leur fonction posturelle. Un test d'examen de la posture est ici proposé sur une base comparative de séméiologie et de radiologie.

Summary Summing up normal posture and its pathological deviations requires accurate knowledge of the anatomy of the various body structures. The same is true of the understanding of the active forces which influence the upright position of the body. An extensive examination methodology is described, resulting from comparisons of clinical and radiological tests.

Zusammenfassung Die Beurteilung der normalen Haltung und deren pathologischen Abweichungen setzt genaue anatomische Kenntnisse der verschiedenen Körperstrukturen voraus. Dasselbe gilt für die Erkenntnis der aktiven Kräfte, die für die Aufrechterhaltung des Körpers wirksam sind. Anhand von klinischen und röntgenologischen Vergleichsuntersuchungen wird hiemit eine eingehende Untersuchungsmethodik vorgelegt.

Electronic Resource

1420-911X

Springer Online Journal Archives 1860-2000

Medicine

Summary The human posture can be considered as an act of balance between different structures of the body. In particular, special reference is given to the biomechanical properties of the anatomical structures as well as to the relationship between the intrinsic and the extrinsic equilibrium of the spine which is very important. The author recommends to build a model with the similar physical properties of the spine where both forces can be shown, and this improve the knowledge of the mechanical properties which make the human posture possible.

Zusammenfassung Die menschliche Haltung wird als «act of balance» zwischen den verschiedenen Körperteilen angesehen. Es wird insbesondere auf die biomechanischen Eigenschaften der anatomischen Struktur hingewiesen sowie auf die Bedeutung des «intrinsic und extrinsic» Equilibriums der Wirbelsäule. Es wird schließlich die Herstellung eines Modells der Wirbelsäule empfohlen, mit dem Ziel, die Kenntnisse über die mechanischen Gesetze, die die Haltung ermöglichen, zu vertiefen.

Electronic Resource

1619-6937

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

Zusammenfassung Die Arbeit befaßt sich mit der Entwicklung einer allgemeinen Theorie für eine Mischung von richtungsorientierten Kurven. Stoffgleichungen für einen einfachen viskoelastischen Werkstoff mit verschwindendem Gedächtnis werden hergeleitet. Um die Anwendung der allgemeinen Theorie zu beweisen, wird eine Mischung spezieller orientierter Kurven als ein mathematisches Modell der Wirbelsäule vorgeschlagen. Sodann wird auf Grund einer einfachen nichtlinearen Theorie gezeigt, daß es genügt, das mechanische Verhalten der Wirbelsäule durch ein aus zwei Komponenten zusammengesetzten Stab, mit Längs- und Schubdehnung, Biegungs- und Verdrehungsdeformation, darzustellen.

Summary A general nonlinear theory of a mixture of interacting directed curves is developed. Constitutive equations are presented for a class of viscoelastic materials with fading memory. A model of the ligamentous spine as a composite or mixture of directed curves is proposed. Suitable constraints are imposed which yield a simple nonlinear theory governing the response of the spine regarded as a composite rod which can undergo bending, twisting, axial extension and cross-sectional shear deformation.

Electronic Resource