Both sides of human cerebellum involved in preparation and execution of sequential movements.

Using an event-related fMRI procedure, we investigated the role of the human cerebellum in sequential finger movements. Subjects performed a delayed sequential finger movement task in which an instructive cue preceded the imperative signal by 16.5 s. Bilateral activation was observed in the cerebellum following both the cue and imperative signals. The activated regions overlapped within the cerebellum, extending across intermediate and lateral regions corresponding to lobules HV-HVII. In contrast, activation in primary motor cortex was primarily restricted to the execution phase and most prominent in the contralateral hemisphere. These results indicate that the cerebellum is bilaterally recruited for the preparation and execution of sequential movements.

Effects of semantic discrimination of Chinese words on N400 component of event-related potentials.

20 subjects' event-related brain potentials were measured during a lexical decision task in which Chinese characters were used in both conditions of related (antonym) and unrelated words. Analysis indicated that the mean reaction time for unrelated words was 130 msec. longer than that elicited by related words. The condition of unrelated words elicited a significant N450, and an obvious P500 was evoked by related words at each of the 17 recording sites. Furthermore, the amplitudes of N210 and N450 were larger in the left hemisphere than in the right hemisphere but the amplitude of P500 was larger in the right hemisphere than in the left hemisphere.

SCIRR39 promotes differentiation of oligodendrocyte precursor cells and regulates expression of myelin-associated inhibitory factors.

SCIRR39 is an identified upregulated gene in rat primary neuron injury and/or regeneration process. However, roles of SCIRR39 in the regeneration of central nervous system (CNS) injury are still largely unexplored. Using real-time quantitative PCR and Western blotting, SCIRR39 expression was detected in oligodendrocyte precursor cells (OPCs) and oligodendrocytes. Moreover, the results from cell proliferation and cell cycle indicated that SCIRR39 inhibited OPCs proliferation and induced cell cycle arrest in G0/G1 and G2/M phases. Importantly, SCIRR39 positively regulated OPC differentiation and the expression of myelin basic protein. We also examined the effect of SCIRR39 on expression of myelin-associated inhibitory factors, including myelin-associated glycoprotein (MAG), oligodendrocyte myelin glycoprotein (OMgp), and Nogo A. Nogo A level was markedly regulated by SCIRR39 overexpression or knockdown in oligodendrocytes and cortical neurons co-cultures, while the expression of MAG and OMgp was not obviously changed by SCIRR39 overexpression or knockdown. Taken together, our results indicate the important role of SCIRR39 either in OPC differentiation or in axon myelination, and may provide a new therapeutic target for the treatment of CNS injury.

Left-lateralized N170 response to unpronounceable pseudo but not false Chinese characters-the key role of orthography.

A negative event-related potential (ERP) component, known as N170, can be readily recorded over the posterior left brain region when skilled readers are presented with visual words. This left-lateralized word-related N170 has been attributed either to linguistic processes, particularly phonological processing, or to the role of orthographic regularity, emphasizing a perceptual origin. This debate, however, is difficult to resolve in the context of alphabetic scripts because of the tight relations between orthography and phonology. In contrast, Chinese characters have arbitrary mappings between orthographic and sound forms, making it possible to tease apart these two properties of visual words. We therefore addressed this issue by examining ERP responses to Chinese characters and three types of structurally matched but unpronounceable stimuli: pseudo-characters, false-characters, and stroke combinations. A content-irrelevant color matching task was adopted to minimize potentially different top-down modulations across stimulus types. Results show that, relative to false-characters and stroke combinations, real- and pseudo-characters evoked greater N170 in the left posterior brain region. Critically, despite being unpronounceable, pseudo-characters produced the same amplitude and left-lateralized N170, just as real-characters. These results provide strong evidence that orthography rather than phonology serves as the main driver for the enhanced and left-lateralized N170 to visual words.

Specific recognition of DNA by small molecules.

DNA exhibits many attractive features in the development of drug design and disease treatment, and there are some successful events for drugs targeting to DNA in clinic use. Nowadays, the specific recognition of DNA by small molecules is the crucial factor of the sustainable development of DNA-target drugs, for the serious side-effects of existing drugs. In this review, we discussed the current efforts of DNA-drug specific interaction that concerned with various DNA recognition models, such as abasic, mismatch or bulge site recognition, specific sequence recognition, and secondary structure recognition. Some compounds are found to show a remarkable potential to be an ideal drug.

Cerebral response to patient's own name in the vegetative and minimally conscious states.

BACKGROUND: A challenge in the management of severely brain-damaged patients with altered states of consciousness is the differential diagnosis between the vegetative state (VS) and the minimally conscious state (MCS), especially for the gray zone separating these clinical entities. OBJECTIVE: To evaluate the differences in brain activation in response to presentation of the patient's own name spoken by a familiar voice (SON-FV) in patients with VS and MCS. METHODS: By using fMRI, we prospectively studied residual cerebral activation to SON-FV in seven patients with VS and four with MCS. Behavioral evaluation was performed by means of standardized testing up to 3 months post-fMRI. RESULTS: Two patients with VS failed to show any significant cerebral activation. Three patients with VS showed SON-FV induced activation within the primary auditory cortex. Finally, two patients with VS and all four patients with MCS not only showed activation in primary auditory cortex but also in hierarchically higher order associative temporal areas. These two patients with VS showing the most widespread activation subsequently showed clinical improvement to MCS observed 3 months after their fMRI scan. CONCLUSION: The cerebral responses to patient's own name spoken by a familiar voice as measured by fMRI might be a useful tool to preclinically distinguish minimally conscious state-like cognitive processing in some patients behaviorally classified as vegetative.

Plasma propofol concentrations during orthotopic liver transplantation.

OBJECTIVE: The aim of this study was to investigate the changes in plasma concentrations of propofol in three phases (the paleohepatic, anhepatic, and neohepatic phases) during orthotopic liver transplantation (OLT) using target-controlled infusion (TCI). METHODS: Ten patients undergoing OLT without venovenous bypass were studied (age 29-53 years, weight 56-79 kg). After intubation, a non-hypnotic target concentration of propofol 0.5 microg ml(-1) using a Diprifusor pump (Zeneca Pharmaceuticals, Macclesfield, UK) was administered as a supplement anesthesia throughout the procedure. Plasma samples were obtained in each phase for propofol assay, respectively. Performance parameters for the Diprifusor system in each phase, the percentage median performance error (MDPE), the percentage median absolute performance error (MDAPE), and the percentage median absolute constancy error (MDACE) were evaluated. RESULTS: In all patients, measured plasma propofol concentrations were several times higher than Diprifusor values in each phase during the procedure. In nine patients, propofol concentrations in the anhepatic phase were higher than those in the paleohepatic or neohepatic phase (P < 0.05). There were no significant differences between the paleohepatic and neohepatic phases. Interindividual variation of the plasma propofol concentrations was significant (P < 0.05). Percentage median performance error of Diprifusor in each phase, as well as MDAPE, was large (>300%) and was significantly higher in the anhepatic phase (P < 0.01), whereas MDACE was relatively small and there was no significant difference between phases. CONCLUSIONS: Models used by Diprifusor are not suitable for liver transplantation patients. A further study should be performed in order to determine all pharmacokinetic parameters of propofol in these patients.

Effect of immuno-modulating agents on murine IL-2 production.

The effect of two Chinese traditional drugs, Dang Gui injection prepared from Angelica sinensis and C 21 Ester glucoside (GB) extracted from Cynanchus auriculatus on in vitro production of IL-2 has been studied. The IL-2 was produced by Con A stimulation of mouse spleen mononuclear cells. The IL-2 activity was assayed using Con A stimulated blast cells as the target. It was found that Dang Gui increased and GB decreased the production of IL-2. In the control experiments for immuno-modulating effect, prostaglandin E2 (PGE2) was found to suppress and indomethacin to increase IL-2 production. The stimulatory effect of Dang Gui was totally abrogated by PGE2.

Inhibitory effect of monocytes on "lymphokine activated killer" (LAK) cell activity.

The effects of placing activated monocytes in the presence of LAK cells was investigated. It was shown that the addition of monocytes to a preparation of rIL2-stimulated lymphocytes decreased LAK cell activity. This inhibition is enhanced in the presence of rIFN gamma. To analyze the mechanisms of inhibition, monocytes and lymphocytes were cultured separately, on opposite sides of a porous membrane which allowed the passage of molecules. Under such conditions, monocytes inhibited the activity of LAK cells to the same degree that a mixed culture does, suggesting a possible role of diffusible factor(s). Neither indomethacin nor PGE2 fully inhibited LAK cell activity, indicating that PGE2 is not the major monocyte-derived factor inhibiting LAK cell activity. It was also demonstrated that LAK cells can kill monocytes, but that IFN gamma can protect the monocyte from the toxic effect. This protective mechanism may be responsible for enhancing the inhibitory activity of monocytes.