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排序方式: 共有4699条查询结果,搜索用时 15 毫秒
21.
Anders Persson Stefan Pauli Christer Halldin Sharon Stone-Elander Lars Farde Irene Sjgren Gran Sedvall 《Human psychopharmacology》1989,4(1):21-31
The 11C-labelled benzodiazepine antagonist Ro 15–1788 (flumazenil) and positron emission tomography (PET) were used to determine quantitative characteristics of benzodiazepine receptor binding in the neocortex of healthy young men. Saturating doses of unlabelled flumazenil administered i.v., before or together with the ligand-reduced 11C-flumazenil accumulation in the neocortex by about 90 per cent. Saturating doses of unlabelled flumazenil had little effect on the accumulation of radioactivity in the benzodiazepine receptor-poor regions such as pons or white matter. By giving graded doses of unlabelled flumazenil together with the tracer, saturation isotherms were obtained allowing the calculation of receptor density (Bmax) and equilibrium dissociation constant (Kd) values on the basis of certain assumptions Bmax values were in the order of 90 pmol/g and Kd values in the order of 10 nM in the neocortex. Scatchard and Hill plots of the radioactivity data indicated that 11C-flumazenil binds to saturable sites of a homogeneous population. The data indicate that intravenous doses of 1 or 2 mg flumazenil result in a benzodiazepine receptor occupancy of about 50 per cent. The method described should be useful for studying regional differences in benzodiazepine receptor characteristics in the living human brain in healthy subjects and neuropsychiatric disorders, and also in relation to treatment with drugs interacting with benzodiazepine receptors. 相似文献
22.
Petru Liuba Jerker Persson Jukka Luoma Seppo Yl?-Herttuala Erkki Pesonen 《European heart journal》2003,24(6):515-521
BACKGROUND: Atherosclerosis begins early in life. Infections might contribute to the pathogenesis of atherosclerosis. In this study, we investigated whether acute infections in children could alter the carotid wall morphology and the lipid profile. METHODS: Mean carotid intima-media thickness (IMT) was measured by high-resolution ultrasound in 28 hospitalised children (mean age: 5+/-2 years), who fulfilled the diagnostic criteria of acute infections (body temperature, >38 degrees C; C-reactive protein, >15mg/ml, and clinical), and in 20 age- and gender-matched controls. Antibodies against oxidised low-density lipoprotein (anti-oxLDL antibodies), as well as total and high-density lipoprotein cholesterol (HDL-C) were analysed in all children. The infection group was investigated both during the acute illness and 3 months after clinical recovery (post-infection). RESULTS: During the acute illness, the infection group had elevated anti-oxLDL antibodies and decreased HDL-C, as compared to those obtained at 3 months and in controls (p<0.05). These changes in the infection group were followed, at 3 months, by thickening of carotid intima-media. Those who received antibiotics during their acute illness had less carotid thickening than those who were not treated with antibiotics (p<0.05). CONCLUSION: Acute infections in children seem to be accompanied by enhanced oxidative modification of LDL and by decrease in HDL-C. These lipid changes may be followed by thickening of carotid artery intima-media. These findings suggest that, in childhood, acute infections could be associated with increased risk of atherosclerosis, and warrant further studies on this topic. 相似文献
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To study the intracellular transport and targeting to the Golgi complex of the membrane glycoproteins G1 and G2 of Hantaan virus, we have expressed them together and separately using recombinant vaccinia viruses. When expressed from the same recombinant vaccinia virus, G1 and G2 were localized to the Golgi complex as analyzed by both immunofluorescence and subcellular fractionation. However, when the glycoproteins were expressed from separate recombinant viruses, both proteins remained in the endoplasmic reticulum. Using several monoclonal antibodies, it was found that G1 expressed alone did not acquire its correct conformation. Finally, if cells were coinfected with G1- and G2-expressing recombinant viruses, the proteins were again targeted to the Golgi complex. The N-linked glycans remained in all cases largely endoglycosidase-H sensitive. With none of the recombinant viruses were expression of the glycoproteins observed on the cell surface. Neither did chasing in the presence of cycloheximide result in the surface expression of G1 or G2. Our results indicate that for transport out of the endoplasmic reticulum and proper targeting to the Golgi complex, the two glycoproteins have to be coexpressed. The most likely interpretation is that G1 and G2 have to interact with each other in the endoplasmic reticulum in order to become transport competent. 相似文献
25.
Two hundred and ten patients with clinical evidence of heartfailure, developing after an acute myocardial infarction, wererandomized to treatment with the ß1 antagonist metoprolol50100mg b.i.d. (n=106) or the ß1 partial agonistxamoterol 100200 mg bid. (n=104). Left ventricular systolicand diastolic function were assessed with echocardiography andtransmitral Doppler cardiography before and after 3 and 12 monthsof double-blind treatment. E-point septal separation and percent left ventricular fractional shortening were used as indicesof systolic function. The ratio between peak early and latemitral diastolic flow (E/A ratio) and isovolumic relaxationtime were used as indices of diastolic function. In the xamoterol group, there was a deterioration in E-pointseptal separation (P<0·05). A difference between thetreatment groups was present both at 3 months (E-point septalseparation 11·4 vs 13·0 mm, P<0·0l,fractional short ening 271 vs 252%, P<005) and 12 months(E-point septal separation Ill vs 13·2 mm, P<0·05fractional shortening 26·9 vs 25·0%, P<0·05).E/A ratio increased in the metoprolol group (P<0·05)but not in the xamoterol group. At 3 months there was a significantdifference (0·85 vs 0·67, P<0·005 betweenthe groups but not at 12 months. In comparison with the ß1-receptor antagonist metoprolol,the ß1 partial agonist xamoterol impaired left ventricularsystolic function in patients with clinical evidence of heartfailure after an acute myocardial infarction. 相似文献
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28.
Viktoria Werkström Lars Ny Katarina Persson K.-E. Andersson 《Naunyn-Schmiedeberg's archives of pharmacology》1997,356(2):151-158
Neuronal regulation of smooth muscle tone in the female pig urethra has mainly been studied in vitro using electrical field
stimulation (EFS) of nerves. Excitatory control is considered to be exerted by released noradrenaline, whereas inhibitory
control is non-adrenergic non-cholinergic (NANC), and mediated by nitric oxide (NO), and an as yet unidentified agent. We
investigated the functional and morphological effects of α-latrotoxin (αLTX), a spider neurotoxin believed to cause massive
release of vesicle-stored neurotransmitters, on spontaneously developed urethral smooth muscle tone. The effects were compared
to those of EFS and high potassium. In the presence of the NO-synthesis inhibitor Nω-nitro-L-arginine (L-NOARG: 0.3 mM) both αLTX and EFS evoked contractions. After treatment with scopolamine and phentolamine,
no contraction was observed, and under these conditions αLTX and EFS induced relaxation. At low frequencies (<12 Hz), the
EFS-induced relaxations were rapid, whereas at higher frequencies (>12 Hz), they were biphasic, consisting of a rapid first
phase followed by a more long-lasting second phase. L-NOARG abolished the relaxations at low frequencies, as well as the first
phase of the biphasic relaxation. The second phase was not affected by treatment with L-NOARG, but 0.1 μM ω-conotoxin GVIA,
blocker of N-type voltage-operated calcium- channels (VOCCs), markedly reduced or abolished the response. In the presence
of L-NOARG or ω-conotoxin GVIA, the αLTX-induced relaxation was significantly decreased, and the combination of L-NOARG and
ω-conotoxin GVIA further reduced or abolished the relaxation. In preparationstreated with tetrodotoxin or scorpion venom,
believed to inactivate nerves by acting on sodium channels, αLTX and EFS had no effects. αLTX-induced relaxation was not associated
with changes in cyclic GMP or cyclic AMP content. High (80 mM) potassium solution induced a triphasic response of the preparation.
A transient relaxation was followed by a restoration of tone, and then by a persistent relaxation. The persistent relaxation
was slightly reduced by scorpion venom or L-NOARG, but reduced by 50% by a combination of L-NOARG and ω-conotoxin GVIA. Ultrastructural
analysis of the urethral circular smooth muscle layer revealed a moderate amount of nerve profiles supplying the smooth muscle.
In control preparations, the nerve profiles contained both small synaptic vesicles and large dense core vesicles. αLTX caused
a major loss of both types of vesicle. The present data suggest that αLTX has the ability to release not only adrenergic and
cholinergic transmitters, but also NANC mediators of relaxation, including NO, from nerve terminals in the urethra.
Received: 13 January 1997 / Accepted: 17 April 1997 相似文献
29.
The metabolic fate of the benzodiazepine antagonist RO 15-1788 labelled with 11C was studied in plasma from human subjects after intravenous administration in connection with positron emission tomography. Ro 15–1788 and its metabolites were separated by thin-layer chromatography and the radioactivity in the different compounds was determined. 11C-Ro 15–1788 was extensively and rapidly metabolised to the corresponding free acid. At 36 minutes after administration only 50% of the radioactivity in plasma represented unchanged compound. 相似文献
30.
Septic separation of the symphysis pubis 总被引:1,自引:1,他引:0
Summary Symphysial osteomyelitis has been distinguished from osteitis pubis because of the more serious nature of the disease. We report a case in which there was a pelvic separation similar to that seen after trauma or pregnancy. The previously undescribed complications of bladder perforation and pelvic instability are also noted. There was no predisposing cause in this case, in contrast to the 40 previously reported. The causative organism was staphylococcus aureus, but pseudomonas aeruginosa and escherichia coli have also been found in other cases.
Résume L'ostéomyélite de la symphyse pubienne a pu être distinguée de l'ostéite pubienne en raison de sa plus grande gravité. Nous en rapportons un cas dans lequel existait une disjonction symphysaire semblable à celles que l'on observe après traumatisme ou grossesse. On a également noté des complications jamais décrites, à savoir une perforation vésicale et une instabilité pelvienne. Il n'y avait pas de cause prédisposante dans ce cas, contrairement aux 40 observations précédemment rapportées dans la littérature. La bactérie causale était un staphylocoque doré, mais le pyocyanique et le colibacille ont également été retrouvés dans d'autres cas.相似文献