排序方式: 共有46条查询结果,搜索用时 15 毫秒
1.
Bernardi Laura Bertuccelli Margherita Formaggio Emanuela Rubega Maria Bosco Gerardo Tenconi Elena Cattelan Manuela Masiero Stefano Del Felice Alessandra 《European archives of psychiatry and clinical neuroscience》2021,271(1):199-210
European Archives of Psychiatry and Clinical Neuroscience - Fibromyalgia syndrome (FMS) is a complex pain disorder, characterized by diffuse pain and cognitive disturbances. Abnormal cortical... 相似文献
2.
Avesani M Formaggio E Fuggetta G Fiaschi A Manganotti P 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2008,187(1):17-23
The mechanisms responsible for changes in brain function during normal sleep are poorly understood. In this study, we aimed
to investigate the effects of sleep on human corticospinal excitability by estimating resting motor threshold (RMT), and latency
and amplitude of motor-evoked potentials (MEPs) after delivering transcranial magnetic stimulation (TMS) in ten healthy subjects.
We also aimed to study short-interval intracortical inhibition (SICI) during sleep with paired-pulse TMS (pp-TMS). Ten healthy
volunteers were studied. They were monitored immediately before, during and after a 3-h sleep (from 1 p.m. to 4 p.m., immediately
after the mid-day meal). EEG was continuously recorded during sleep and the various sleep stages were identified off line.
Every 10 min, subjects received ten single stimuli (to estimate RMT, MEP latency and amplitude) and six paired stimuli (to
estimate SICI). MEP amplitude decreased and latency and RMT increased during the various sleep stages and returned to baseline
values on awakening. Post hoc comparisons showed a significant difference in pp-TMS MEP amplitudes between the sleep and all
the other conditions. The changes in TMS evoked variables during the different sleep stages indicate that during nonrapid
eye movement sleep, cortical pyramidal neuron excitability (as measured by RMT, MEP latency and amplitude) progressively diminishes
and the efficiency of the intracortical GABA-ergic network (as assessed by three pp-TMS) increases. On awakening, these sleep-induced
changes in corticospinal excitability return rapidly to values observed during wakefulness. 相似文献
3.
Formaggio E Storti SF Avesani M Cerini R Milanese F Gasparini A Acler M Pozzi Mucelli R Fiaschi A Manganotti P 《Brain topography》2008,21(2):100-111
Electroencephalography combined with functional magnetic resonance imaging (EEG-fMRI) may be used to identify blood oxygenation
level dependent (BOLD) signal changes associated with physiological and pathological EEG event. In this study we used EEG-fMRI
to determine the possible correlation between topographical movement-related EEG changes in brain oscillatory activity recorded
from EEG electrodes over the scalp and fMRI-BOLD cortical responses in motor areas during finger movement. Thirty-two channels
of EEG were recorded in 9 subjects during eyes-open condition inside a 1.5 T magnetic resonance (MR) scanner using a MR-compatible
EEG recording system. Off-line MRI artifact subtraction software was applied to obtain continuous EEG data during␣fMRI acquisition.
For EEG data analysis we used the event-related-synchronization/desynchronization (ERS/ERD) approach to investigate where
movement-related decreases in alpha and beta power are located. For image statistical analysis we used a general linear model
(GLM) approach. There was a significant correlation between the positive-negative ratio of BOLD signal peaks and ERD values
in the electrodes over the region of activation. We conclude that combined EEG-fMRI may be used to investigate movement-related
oscillations of the human brain inside an MRI scanner and the movement-related changes in the EMG or EEG signals are useful
to identify the brain activation sources responsible for BOLD-signal changes. 相似文献
4.
F. Formaggio V. Moretto M. Crisma C. Toniolo B. Kaptein Q.B. Broxterman 《Chemical biology & drug design》2004,63(2):161-170
Abstract: The novel Cα‐tetrasubstituted α‐amino acid Cα‐methyl, Cα‐cyclohexylglycine was prepared by hydrogenation of its Cα‐methyl, Cα‐phenylglycine precursor. Terminally protected homodi‐, homotri‐, and homotetrapeptides from Cα‐methyl, Cα‐cyclohexylglycine and co‐oligopeptides to the pentamer level in combination with Gly or α‐aminoisobutyric acid residues were prepared by solution methods and fully characterized. The results of a conformational analysis, performed by use of Fourier transform infrared (FT‐IR) spectrophotomet absorption, 1H NMR, and X‐ray diffraction techniques, support the contention that this Cα‐methylated, Cβ‐trisubstituted aliphatic α‐amino acid is an effective β‐turn and 310‐helix inducer in tri‐ and longer peptides as its Cα‐methyl valine parent compound, but partially divergent from the corresponding aromatic Cα‐methyl, Cα‐diphenylmethylglycine residue, known to promote folded and fully extended structures to a significant extent in these oligomers. 相似文献
5.
Seven cases of supratentorial meningiomas are reported. CT-Scan showed irregular hypo-hyperdense zones and features of intratumoral cysts. At surgery a well circumscribed tumor has always been found and easily removed "en bloc". In two cases stereotaxic biopsy was performed previously. CT-Scan findings of meningiomas with microcystic structure and/or necrotic areas may mimic a malignant glioma and lead to an incorrect presumptive diagnosis: then, both therapy and prognosis will be very different. It comes that stereotaxic biopsy is mandatory in all suspected cases of cerebral tumors, in the absence of classical angiographic patterns. 相似文献
6.
Hemoglobin Concentration Affects Electroencephalogram During Cardiopulmonary Bypass: An Indication for Neuro‐Protective Values 下载免费PDF全文
7.
8.
C. Peggion E. Mossel F. Formaggio M. Crisma B. Kaptein Q.B. Broxterman J. Kamphuis C. Toniolo 《Chemical biology & drug design》2000,55(3):262-269
Abstract: Using a chemo‐enzymatic approach we prepared the highly lipophilic, chiral, Cα‐methylated α‐amino acid (αMe)Aun. Two series of terminally protected model peptides containing either d ‐(αMe)Aun in combination with Aib or l ‐(αMe)Aun in combination with Gly were synthesized using solution methods and fully characterized. A detailed solution conformational analysis, based on FT‐IR absorption, 1H NMR and CD techniques, allowed us to determine the preferred conformation of this amino acid and the relationship between chirality at its α‐carbon atom and screw sense of the helix that is formed. The results obtained strongly support the view that d ‐(αMe)Aun favors the formation of the left‐handed 310‐helical conformation. 相似文献
9.
B. Pispisa L. Stella M. Venanzi A. Palleschi A. Polese F. Formaggio C. Toniolo 《Chemical biology & drug design》2000,56(5):298-306
Abstract: In continuation of our studies on the determination of the structural features of functionalized peptides in solution by combining time‐resolved fluorescence data and molecular mechanics results, the conformational properties of a series of linear, homo‐Aib peptides in methanol (a structure‐supporting solvent) were investigated. These compounds have the general formula P(Aib)nN, where Aib is α‐aminoisobutyric acid, N is naphthalene and P is the monomethylated protoporphyrin IX, the two latter chromophores being covalently attached to the peptide C‐ and N‐termini, respectively, while n = 3, 6 and 9. According to 1H NMR and IR spectra, the peptides investigated largely populate a 310‐helical structure in CDCl3, which is also a structure‐supporting solvent. Both steady‐state and time‐resolved fluorescence measurements show a strong quenching of the N emission that parallels an increase of the P fluorescence intensity, suggesting the occurrence of long‐range energy transfer from 1N* to ground‐state P. Comparison of quenching efficiencies and lifetime pre‐exponents with those obtained theoretically from the deepest energy minimum conformers is very satisfactory. The computed structures, built up by partially taking into account the solvent medium, exhibit a rigid, highly compact arrangement, owing to both the 310‐helix conformation of the backbone chain and the very few peptide‐to‐chromophore covalent linkages. As a result, only one or two stable conformations for each peptide were theoretically found, in full agreement with the time‐resolved fluorescence data. Orientational effects between the probes must be taken into account for a correct interpretation of the fluorescence decay results, which implies that interconversion among conformational substates of the N linkages is slower than 10 ns, corresponding to the upper limit of the energy transfer characteristic time. 相似文献
10.
A. Moretto F. Formaggio M. Crisma C. Toniolo M. Saviano E. Benedetti R. Iacovino R.M. Vitale 《Chemical biology & drug design》2001,57(4):307-315
Abstract: Two complete series of N‐protected oligopeptide esters to the pentamer level from 1‐amino‐cyclodecane‐1‐carboxylic acid (Ac10c), an α‐amino acid conformationally constrained through a medium‐ring Cαi ? Cαi cyclization, and either the l ‐Ala or Aib residue, along with the N‐protected Ac10c monomer and homo‐dimer alkylamides, were synthesized using solution methods and fully characterized. The preferred conformation of these model peptides was assessed in deuterochloroform solution using FT‐IR absorption and 1H NMR techniques. Furthermore, the molecular structures of two derivatives (Z‐Ac10c‐OH and Fmoc‐Ac10c‐OH) and two peptides (the dipeptide ester Z‐Ac10c‐l ‐Phe‐OMe and the tripeptide ester Z‐Aib‐Ac10c‐Aib‐OtBu) were determined in the crystal state using X‐ray diffraction. The experimental results support the view that β‐bends and 310‐helices are preferentially adopted by peptides rich in Ac10c, the third largest cycloaliphatic Cα,α‐disubstituted glycine known. This investigation allowed us to complete a detailed conformational analysis of the whole 1‐amino‐cycloalkane‐1‐carboxylic acid (Acnc, with n = 3–12) series, which represents the prerequisite for our recent proposal of the ‘Acnc scan’ concept. 相似文献