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排序方式: 共有1031条查询结果,搜索用时 109 毫秒
1.
Barnett JC Hurd WW Rogers RM Williams NL Shapiro SA 《Journal of minimally invasive gynecology》2007,14(5):664-72; quiz 673
2.
Leonardo Bonilha MD PhD Paulien M. de Vries Diana J. Vincent MD PhD Chris Rorden MD PhD Paul S. Morgan Mark W. Hurd PhD Nada Besenski MD Kenneth J. Bergmann MD Vanessa K. Hinson MD PhD 《Movement disorders》2007,22(8):1110-1116
We investigated whether structural white matter abnormalities, in the form of disruption of axonal coherence and integrity as measured with diffusion tensor imaging (DTI), constitute an underlying pathological mechanism of idiopathic dystonia (ID), independent of genotype status. We studied seven subjects with ID: all had cervical dystonia as their main symptom (one patient also had spasmodic dysphonia and two patients had concurrent generalized dystonia, both DYT1‐negative). We compared DTI MR images of patients with 10 controls, evaluating differences in mean diffusivity (MD) and fractional anisotropy (FA). ID was associated with increased FA values in the thalamus and adjacent white matter, and in the white matter underlying the middle frontal gyrus. ID was also associated with increase in MD in adjacent white matter to the pallidum and putamen bilaterally, left caudate, and in subcortical hemispheric regions, including the postcentral gyrus. Abnormal FA and MD in patients with ID indicate that abnormal axonal coherence and integrity contribute to the pathophysiology of dystonia. These findings suggest that ID is not only a functional disorder, but also associated with structural brain changes. Impaired connectivity and disrupted flow of information may contribute to the impairment of motor planning and regulation in dystonia. © 2006 Movement Disorder Society 相似文献
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Ca2+ dependence of the amphetamine, nomifensine, and Lu 19-005 effect on in vivo dopamine transmission 总被引:1,自引:0,他引:1
The present in vivo microdialysis study examined the role of vesicular- and carrier-mediated mechanisms underlying dopamine (DA) release, uptake and metabolism in halothane-anaesthetized rats. Omission of calcium (Ca2+) from the dialysis perfusing medium, thereby reducing the concentration of Ca2+ in the striatal microenvironment necessary for vesicular DA release, attenuated the elevation of DA normally induced by the potent DA uptake inhibitors, nomifensine and Lu 19-005. Consistent with the results of in vitro studies, amphetamine release DA in a Ca2+-independent manner. The release of DA induced by amphetamine could be effectively blocked by nomifensine and Lu 19-005, demonstrating that the in vivo movement of amines occurred via a transport carried-mediated mechanism. Additionally, the inhibition of DA metabolism produced by amphetamine could be reversed or blocked by prior or delayed treatment with DA uptake inhibitors. The results support a bidirectional in vivo capability of the amine transport carrier. 相似文献
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It is shown that a repetitive pulse sequence consisting of two 90° pulses and gradients in a 1:2 ratio around the second 90° pulse generates interscan shifted stimulated echoes (SSTEs) and intrascan multiple spin echoes (MSEs). Separation of these two types of signals is accomplished using specific gradient crusher schemes. The intensity of the SSTEs is an order of magnitude larger than that of the MSEs and determines the signal contrast if both effects are selected simultaneously. The SSTE sequence generates improved contrast between gray and white matter, even at high field, which is explained in terms of increased inverse T1-weighting for the interscan echo. The MSE image has low signal to noise and no detectable contrast. The effect of interscan diffusion weighting is also discussed. 相似文献
7.
G W Machiedo T Hurd B F Rush G Dikdan J McGee T Lysz 《Archives of surgery (Chicago, Ill. : 1960)》1988,123(4):424-427
To determine whether hepatic dysfunction in sepsis results from hypoperfusion or direct cellular injury, Sprague-Dawley rats underwent either cecal ligation and puncture or sham operation. After either two or six hours, effective hepatic blood flow was measured using the galactose clearance method. Hepatocytes were isolated and intracellular sodium and potassium and glucose production were measured. Hepatic blood flow in septic rats decreased as early as two hours after sepsis when compared with sham-operated rats (3.8 +/- 1.4 vs 8.7 +/- 3.1 mL/min/100 g body weight). Intracellular sodium and potassium levels and glucose production in septic rats were not significantly different when compared with controls at two hours. After six hours, hepatic blood flow remained depressed and intracellular sodium level was increased compared with sham-operated rats (41.7 +/- 10.4 vs 31.4 +/- 5.9 mmol/L [41.7 +/- 10.4 vs 31.4 +/- 5.9 mEq/L]) and potassium decreased compared with controls (90.7 +/- 7.9 vs 111.5 +/- 6.7 mmol/L [90.7 +/- 7.9 vs 111.5 +/- 6.7 mEq/L]). Glucose production was decreased in septic rats after six hours when compared with controls (4.7 +/- 1.5 vs 15.4 +/- 6.4 mumol/g hepatocytes). These data suggest that hepatic blood flow is decreased before alterations in intracellular sodium and potassium as well as glucose production. 相似文献
8.
William W. Hurd MD Lei Wang BSc Mark T. Schemmel MD 《American journal of obstetrics and gynecology》1995,173(6):1731-1733
OBJECTIVE: Our purpose was to compare the relative risk of vessel injury after use of a 5 mm conical-tipped trocar, a 5 mm pyramidal-tipped trocar, and a 10 mm pyramidal-tipped trocar in a rabbit vessel model.STUDY DESIGN: Plastic templates were placed in front of and behind 108 mesenteric vessels in 11 anesthetized New Zealand White rabbits. Laparoscopic trocars were inserted through the templates and mesentery. The incidence of vessel injury was determined at distances from the vessels ranging from 0 to 5 mm.RESULTS: The 5 mm conical trocar resulted in a vessel injury rate of 88% at 0 mm from the vessel but 0% at 1 or 2 mm. The 5 mm pyramidal trocar resulted in 100%, 88%, and 62% injury rates of 0, 1, and 2 mm from the vessels, respectively. The 10 mm pyramidal trocar resulted in a 100% injury rate at 0, 1, 2, or 3 mm from the vessels and 80% and 40% at 4 mm and 5mm, respectively.CONCLUSION: The relative risk of vessel injury is significantly increased by the use of pyramidal-tipped trocars when compared with conical-tipped trocars, especially if larger diameter trocars are used. 相似文献
9.
DeBruyne J Hurd MW Gutiérrez L Kaneko M Tan Y Wells DE Cahill GM 《Journal of neurogenetics》2004,18(2):403-428
Widespread use of zebrafish (Danio rerio) in genetic analysis of embryonic development has led to rapid advances in the technology required to generate, map and clone mutated genes. To identify genes involved in the generation and regulation of vertebrate circadian rhythmicity, we screened for dominant mutations that affect the circadian periodicity of larval zebrafish locomotor behavior. In a screen of 6,500 genomes, we recovered 8 homozygous viable, semi-dominant mutants, and describe one of them here. The circadian period of the lager and lime (lag(dg2)) mutant is shortened by 0.7 h in heterozygotes,and 1.3 h in homozygotes. This mutation also shortens the period of the melatonin production rhythm measured from cultured pineal glands, indicating that the mutant gene product affects circadian rhythmicity at the tissue level, as well as at the behavioral level. This mutation also alters the sensitivity of pineal circadian period to temperature, but does not affect phase shifting responses to light. Linkage mapping with microsatellite markers indicates that the lag mutation is on chromosome 7. A zebrafish homolog of period1(per1) is the only known clock gene homolog that maps near the lag locus. However, all sequence variants found in per1 cDNA from lag(dg2) mutants are also present in wild type lines, and we were unable to detect any defect in per1 mRNA splicing, so this mutation may identify a novel clock gene. 相似文献
10.
Human ovarian granulosa cells and follicular fluid indices: the relationship to oocyte maturity and fertilization in vitro 总被引:1,自引:0,他引:1
The study investigates the correlation between oocyte maturity and
fertilization and a variety of hormonal parameters in follicular fluid and
ovarian granulosa cells. A methodology for purification of granulosa cells
from contaminating blood cells is also established. A total of 63
follicular aspirates were collected at oocyte retrieval from 30 women
superovulated using the long luteinizing hormone- releasing hormone (LHRH
analogue)/human menopausal gonadotrophin regimen. Oestradiol, progesterone,
testosterone and human chorionic gonadotrophin (HCG) were quantified in
follicular fluid and granulosa cells were immunostained for human chorionic
gonadotrophin. Immunopurification of granulosa cells from contaminating
blood cells was performed. HCG in follicular fluid was significantly high
in follicles yielding immature (grade 3) oocytes (P=0.002); there was no
correlation with fertilization. Aspirates from follicles containing mature
(grade 1) oocytes and oocytes that subsequently fertilized had
significantly more granulosa cells immunobound to HCG (P < 0.001,
P=0.02). Moreover, the immunomagnetic purification technique provided
>98% pure population of granulosa cells. The data demonstrate that HCG
in follicular fluid and on granulosa cells may help to predict oocyte
maturity and fertilization. Furthermore, immunomagnetic beads provide a
reliable procedure for the purification of ovarian granulosa cells.
相似文献