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排序方式: 共有508条查询结果,搜索用时 15 毫秒
51.
Kejia Cai Ravi PR Nanga Lisa Lamprou Claudia Schinstine Mark Elliott Hari Hariharan Ravinder Reddy C Neill Epperson 《Neuropsychopharmacology》2012,37(13):2764-2771
Gamma-aminobutyric acid (GABA) and glutamate are implicated in numerous neuropsychiatric and substance abuse conditions, but their spectral overlap with other resonances makes them a challenge to quantify in humans. Gabapentin, marketed for the treatment of seizures and neuropathic pain, has been shown to increase in vivo GABA concentration in the brain of both rodents and humans. Gabapentin effects on glutamate are not known. We conducted a gabapentin (900 mg) challenge in healthy human subjects to confirm and explore its effects on GABA and glutamate concentrations, respectively, and to test the ability of single voxel localized proton magnetic resonance spectroscopy (1H-MRS) to reliably measure GABA and glutamate in the visual cortex at the ultra-high magnetic field of 7 Tesla. Reproducibility of GABA and glutamate measurements was determined in a comparison group without drug twice within day and 2 weeks apart. Although GABA concentration changes were small both within day (average 5.6%) and between day (average 4.8%), gabapentin administration was associated with an average increase in GABA concentration of 55.7% (6.9–91.0%). Importantly, drug-induced change in GABA levels was inversely correlated to the individual''s baseline GABA level (R2=0.72). Mean glutamate concentrations did not change significantly with or without drug administration. In conclusion, localized 1H-MRS at 7 Tesla can be successfully applied to the measurement of GABA concentration and is sensitive to acute drug-induced changes in cortical GABA. Whether baseline GABA concentrations predict clinical efficacy of gabapentin is an area worthy of exploration. 相似文献
52.
我国道路交通事故伤概况 总被引:49,自引:6,他引:49
以公安部交通管理局公布的数据为基础,报告我国近40多年来,道路交通事故及其所致的伤亡不断上升,分别增加了约30倍至50余倍;万车死亡率有明显下降趋势,由1951年的137.64人降至1993年的27.27人,但仍远高于发达国家(<5人),10万人死亡率有增高的趋势,由1951年的0.15人增至1993年的5.29人,但低于发达国家(>7.7人),这显然与我国人均汽车拥有量较少有关。通过分析道路交通 相似文献
53.
54.
Endoscop c manometry of sphincter of Oddi(SO)and serumlevels of gastrin,glucagon,and somatostatin were measured in patients withpostcholecystectomy syndrome(n=12),asymptomatic cholecystectomised pa-tients(n=6),and controlled subjects(n=14).Pentagastrin-stimulated gastricacid secretion test was also performed in part of patients who had symptoms orno symptoms after gallbladder resection.The results showed that the patientsof symptomatic group had hypertonic dyskinesia of SO as shown by deep andwide waves superimposed on high basal pressure plateau of SO.The symptoma-tic group also had a higher serum level of gastrin and a greater BAO than tho-se of other two groups.No difference of serum levels of glucagon and soma-tostatin was found among these three groups.The hypertonic dyskinesia of SOand hypergastrinemia are considered as possibly important factors in the patho-genesis of postcholecystectomy syndrome. 相似文献
55.
We examined if rat myometrial cells in culture generate nitric oxide (NO)
and express various isoforms of NO synthase (NOS). Myometrial cells
isolated from rats on day 18 of gestation were incubated with various
stimulators and inhibitors of NOS for 24 and 48 h, and NO production was
evaluated by measuring nitrites in the media and NOS proteins in the cell
lysates. NO was produced by myometrial cells and its production inhibited
by N(G)-methyl-L-arginine (L-NMMA). This inhibition was reversed by
L-arginine (3 mM). Interleukin-1beta (IL- 1beta) significantly stimulated
NO production, in a dose-dependent manner. The IL-1beta-stimulated NO
production was inhibited by the NOS inhibitor, L-NMMA, whose effects were
reversed by L-arginine. Abundant NOS III protein was detectable in freshly
isolated myometrial cells, and this was maintained in culture in the
presence of fetal bovine serum (FBS; 10%). In the absence of FBS, NOS III
levels decreased significantly (by 90%) within 24 h. In contrast, NOS I and
NOS II proteins were undetectable in freshly isolated muscle cells and in
cells cultured without IL-1beta. However, NOS II protein in these cells was
induced by IL-1beta. Thus, NO is produced by myometrial cells through the
NOS III isoform, and the myometrial NO may be important in maintaining
uterine quiescence during pregnancy.
相似文献
56.
医学生心理健康状况与人格特征的相关分析 总被引:19,自引:4,他引:15
目的 :了解在校医学生的心理健康状况 ,为今后开展心理健教育提供有益的依据。方法 :采用 SCL-90和 EPQ量表对在校 5 88名医学生调查并作相关分析。结果 :医学生出现各类心理问题的比例为 6.80 %~ 3 2 .11% ,以强迫、人际敏感、抑郁和偏执为主。临医和护理专业学生心理问题的侧重点不同。女生在人际敏感、抑郁和恐怖等方面均高于男性。情绪稳定性 N和精神质 P与各因子及总均分呈正相关关系 (P<0 .0 1) ,掩饰度 L 与各因子呈显著负相关 (P<0 .0 1)。多因素回归分析表明 ,情绪稳定性 N和掩饰度 L对心理健康的影响起着重要作用。结论 :搞好学生的心理健康 ,加强健全人格教育是关键 ,同时要根据不同性别和专业区别地对待 相似文献
57.
Gap junction intercellular communication (GJIC) has been measured in cell
lines that represent different stages of chemically induced mouse skin
carcinogenesis. No significant difference in GJIC, as measured by dye
spread, was found in cultures of normal keratinocyte, papilloma or squamous
carcinoma cell lines. There was no correlation, in this system, between the
presence of a mutant Ha-ras gene and down- regulation of communication.
There was, however, a marked decrease in GJIC (80-90%) on progression from
squamous to spindle carcinoma cells. Measurement of GJIC in somatic cell
hybrids shows that the genetic defect responsible for this down-regulation
is recessive and is common to two independently isolated spindle cell
lines. No abnormalities were found in the spindle cells in expression of
connexin 43, a cell component involved in gap junction formation and
permeability. However, expression of E-cadherin, a cell-cell adhesion
molecule implicated in the process of gap junction formation, was missing
in the spindle carcinoma cells. Introduction of an E-cadherin cDNA into the
spindle cells partially restored junctional communication without causing
any noticeable alterations in cell morphology. During the study a non-
tumourigenic keratinocyte line, a sub-clone of a normal keratinocyte line,
was also found to have a low level of GJIC. However, the defect in this
line was shown, by genetic complementation in somatic cell hybrids, to be
different from that in the spindle carcinoma cell lines. Consistent with
these data, analysis by immunofluorescence shows an abnormal distribution
of connexin 43 in these cells.
相似文献
58.
The authors present two cases of percutaneous cecostomy performed with a modified approach previously described for percutaneous gastrostomy and cholecystostomy. T-fastener devices were used to affix the cecum to the anterior abdominal wall; thus, the potential problem of fecal spillage was prevented. In both cases, adequate fecal drainage was provided without complication. 相似文献
59.
60.
YP Panayiotopoulos MD PhD S Padayachee PhD BSC ACE Colchester PhD FRCP PR Taylor MChir FRCS 《International journal of clinical practice》1997,51(6):375-377
In early series the majority of carotid endarterectomies were performed in patients with amaurosis fugax (AFx) or transient ischaemic attacks (TIAs) who were thought to have atheromatous ulcers of the carotid bifurcation or the internal carotid artery (ICA). The degree of stenosis was considered to be of secondary importance. We compared our own data with two British series undertaken in the early and late 80s/early 90s. This reflects the broadening of indications and the change of practice for carotid endarterectomy over the years, on the one hand towards including patients who are at greater risk of perioperative stroke (previous CVAs vs TIAs, crescendo TIAs and stroke in evolution), and on the other towards patients who have had no symptoms attributable to the carotid lesion (asymptomatic cases, combined carotid and cardiac procedures). 相似文献