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11.
Effect of low-frequency repetitive transcranial magnetic stimulation on interhemispheric inhibition 总被引:5,自引:0,他引:5
Pal PK Hanajima R Gunraj CA Li JY Wagle-Shukla A Morgante F Chen R 《Journal of neurophysiology》2005,94(3):1668-1675
We studied the effects of 1-Hz repetitive transcranial magnetic stimulation (rTMS) on the excitability of interhemispheric connections in 13 right-handed healthy volunteers. TMS was performed using figure-eight coils, and surface electromyography (EMG) was recorded from both first dorsal interosseous (FDI) muscles. A paired-pulse method with a conditioning stimulus (CS) to the motor cortex (M1) followed by a test stimulus to the opposite M1 was used to study the interhemispheric inhibition (ppIHI). Both CS and TS were adjusted to produce motor-evoked potentials of approximately 1 mV in the contralateral FDI muscles. After baseline measurement of right-to-left IHI (pre-RIHI) and left-to-right IHI (pre-LIHI), rTMS was applied over left M1 at 1 Hz with 900 stimuli at 115% of resting motor threshold. After rTMS, ppIHI was studied using both the pre-rTMS CS (post-RIHI and post-LIHI) and an adjusted post-rTMS CS set to produce 1-mV motor evoked potentials (MEPs; post-RIHI(adj) and post-LIHI(adj)). The TS was set to produce 1-mV MEPs. There was a significant reduction in post-LIHI (P = 0.0049) and post-LIHI(adj) (P = 0.0169) compared with pre-LIHI at both interstimulus intervals of 10 and 40 ms. Post-RIHI was significantly reduced compared with pre-RIHI (P = 0.0015) but pre-RIHI and post-RIHI(adj) were not significantly different. We conclude that 1-Hz rTMS reduces IHI in both directions but is predominantly from the stimulated to the unstimulated hemisphere. Low-frequency rTMS may be used to modulate the excitability of IHI circuits. Treatment protocols using low-frequency rTMS to reduce cortical excitability in neurological and psychiatric conditions need to take into account their effects on IHI. 相似文献
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Summary A pyrG mutant of Trichoderma viride, a very efficient cellulase producer, was isolated from among 5-fluoroorotic acid-resistant mutants. The mutation was complemented with the pyr4 gene of Neurospora crassa and used as a selection marker for the transformation of T. viride. A plasmid vector, pDJB1-Taa, carrying both the pyr4 gene and a gene encoding Taka-amylase A from Aspergillus oryzae, was constructed and introduced into protoplasts of T. viride pyrG-. The transformation frequency was 1–10 transformants (3 on average) per g DNA. One transformant showed highly elevated -amylase production (about 17 times higher than the recipient level) and the integration of more than one copy of the Taka-amylase gene. 相似文献
13.
Takashi Hirano Shinichi Ohashi Satoshi Morimoto Keishiro Tsuda Tomowo Kobayashi Shigeru Tsukagoshi 《Macromolecular chemistry and physics.》1986,187(12):2815-2824
Polymeric conjugates of adriamycin (ADR) ( 2 ) or daunomycin (DM) ( 3 ) were synthesized by reaction of the drugs with the copolymer of divinyl ether and maleic anyhdride (DIVEMA) ( 1 ). The content of ADR moieties in the DIVEMA conjugate ( 4 ) could be varied depending on the reaction conditions up to 35,8 wt.-%. Considering the low toxicity and the high possibility of renal excretion, DIVEMA with M?w of 7000 and M?w/M?n = 1,6 was used for the conjugation. The rate of drug release from the conjugate was determined under physiological conditions by reversed phase HPLC. Within 14 days only 15% of the attached ADR was released from conjugate 4 . The antitumor activity of the conjugates was tested in vitro and in vivo against mouse P388 leukemia. Conjugate 4 proved to be 28 times less active than ADR in vitro, which could be explained from the slow drug-release. On the contrary 50% of the leukemic mice treated by 4 survived more than 60 days, whereas no mice given ADR alone or the admixture of ADR and DIVEMA survived 30 days. An antitumor activity of the polymeric conjugate better than that of the free drug was also observed in vivo with DM. Such a polymeric effect can be attributed either to the change in body distribution, the difference in pharmacokinetics, or the slow drugrelease. 相似文献
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Tatsuo Sakamoto Hideo Tsukagoshi Peter J. Barnes K. Fan Chung 《Inflammation research》1993,39(3-4):111-117
We have investigated the effects of SR-48968, an NK2 receptor antagonist, and indomethacin, a cyclooxygenase inhibitor, against bronchoconstriction and airway microvascular leakage induced by bradykinin (BK) in anesthetized guinea pigs. In addition, we have determined whether these effects were mediated via bradykinin B2 receptor activation, using a B2 receptor antagonist HOE 140. Lung resistance (R
L) and extravasation of Evans blue dye into airway tissues were used as indexes of airway caliber and microvascular leakage, respectively. BK (15 nmol/kg i.v.) induced a significant increase inR
L and leakage of dye at all airway levels, responses which were completely abolished by HOE 140 (0.13 mg/kg i.v.). SR-48968 (1.5 mg/kg i.v.) had no effect against BK-induced airway effects. Indomethacin (5 mg/kg i.v.) completely blocked the increase inR
L and significantly inhibited the leakage of dye in peripheral intrapulmonary airway. In conclusion, bronchoconstriction induced by i.v. BK is mediated by release of cyclooxygenase products but not by stimulation of NK2 receptors, while the airway microvascular leakage only partly involves cyclooxygenase activation. Cyclooxygenase activation may occur following bradykinin B2 receptor stimulation. 相似文献
16.
Appearance of the LAT protein at an early stage of B-cell development and its possible role
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The linker protein LAT is expressed mainly in T and natural killer (NK) cells. LAT-deficient mice have an arrest of intrathymic T-cell development at the CD4+ CD8+ stage and lack mature T cells in the periphery. However, no gross abnormality in development and function of the B and NK cells has been described. Here we report that LAT is expressed in mouse progenitor B (pro-B) and precursor B (pre-B) cells, but not in immature or mature B cells. LAT in pre-B cells becomes tyrosine phosphorylated upon cross-linking of the pre-B-cell receptor (pre-BCR) by anti- micro antibody. Incubation of 1xN/2b (mouse pre-B-cell line) cells or bone marrow cells from microMT/ microMT mice, which lack B cells after the small pre-B-cell stage, with anti-Ig beta antibody resulted in the downregulation of LAT expression. Transgenic mice which expressed LAT protein in B-lineage cells showed an increased proportion of pro- and large pre-B cells in the bone marrow and a remarkable reduction in the numbers of mature B cells in peripheral lymphoid tissues. Collectively, the present results indicate that LAT is expressed in the cells at the early stages of B-lineage development, but is absent in immature and mature B cells. LAT may play a crucial role in the negative regulation of B-cell development at the transition from pre-B to mature B-cell stages, and signal(s) via the pre-BCR may extinguish LAT expression, thus allowing pre-B-cell differentiation towards the mature B-cell stage. 相似文献
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18.
Summary A 26-year-old male with quadriceps myopathy is presented. He had a family history and only the bilateral quadriceps were wasted, without symptomatic weakness. The specimen of the muscle biopsy showed typical myopathic features without inflammatory reactions. The patchy defect of muscular dystrophin was proved by immunohistochemical study. Dystrophin analysis revealed abnormal 380 kDa dystrophin. Gene deletion was proved at exon 45–48 of Xp21 without frameshift. This case was considered to be a clinical variant form of Becker muscular dystrophy. 相似文献
19.
Ritsuko Akiyama Kunyan Kuang Pablo A. Chiaradía Calvin W. Roberts Jorge Fischbarg 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1997,235(6):384-387
Background: Anterior chamber miotic solutions are widely used in ophthalmic surgery to induce pupillary contraction. We investigated whether the acetylcholine, carbachol, or mannitol present in perfusing solutions can affect corneal endothelial function. Methods: Freshly dissected deepithelized rabbit corneas were mounted in a Dikstein-Maurice chamber at 36 °C. The endothelial sides were perfused with six solutions: (A) 55 mM (1%) acetylcholine Cl plus modified balanced salts; (B) control for A, with acetylcholine Cl replaced by sucrose; (C) 0.55 mM (0.01%) carbachol Cl plus balanced salts; (D) balanced salts solution (BS; control for C); (E) 3% mannitol plus modified balanced salts; and (F) modified balanced salts (control for E, with mannitol replaced by sucrose). Corneal thickness was followed for 3 h in each experiment. The effect of solution E did not differ from that of solution F. Results: The carbachol-containing solution produced a small increase in corneal thickness compared to the control solution, while the acetylcholine-containing solution resulted in corneal thickness lower than that in control preparations. Conclusion: From these data, acetylcholine is harmless to the endothelium, and may actually stimulate its fluid pump mechanism. Carbachol, on the other hand, appears to have a detrimental effect. 相似文献
20.