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991.
Reinaldo Figueroa MD Edilberto Martinez MD Raisa P. Fayngersh MD Hong Jiang MD Hatim A. Omar MD Nergesh Tejani MD Michael S. Wolin PhD 《American journal of obstetrics and gynecology》1995,173(6):1800-1806
OBJECTIVE: Our objective was to determine whether the observed relaxation to lactate and other agents in placental vessels of normal pregnancies is altered in severe preeclampsia.STUDY DESIGN: Isolated placental arteries and veins from women with severe preeclampsia and uncomplicated term pregnancies were precontracted with prostaglandin F2α under 5% oxygen and 5% carbon dioxide with the balance nitrogen (Po2 35 to 38 torr) and then exposed to lactate (1 to 10 mmol/L, pH 7.4, n = 8 to 15), arachidonic acid (0.01 to 10 μmol/L, n = 6 to 13), nitroglycerin (1 nmol to 1 μmol/L, n = 4 to 12), or forskolin (0.01 to 10 μmol/L, n = 6 to 9). The response to lactate was also examined in placental vessels from appropriate-for-gestational-age preterm deliveries (n = 8) for comparison with a similar group with severe preeclampsia (n = 8). The t test and analysis of variance statistics were used.RESULTS: Relaxation to lactate was markedly inhibited in both placental arteries and veins of women with severe preeclampsia compared with vessels from uncomplicated term or preterm pregnancies. Responses to the other relaxing agents were not altered in the severely preeclampsia vessels.CONCLUSIONS: In severe preeclampsia absence of lactate-induced dilatation of placental vessels may contribute to the fetal complications associated with impaired blood flow and vasospasm. 相似文献
992.
Sybille Spicker Jörg B. Schulz Dirk Petersen Michael Fetter Thomas Klockgether Johannes Dichgans 《Journal of neurology》1995,242(8):517-521
Eye movements were studied in 13 patients with Friedreich's ataxia and correlated with MRI findings to investigate whether oculomotor abnormalities can be traced to cerebellar disturbances in this disease. One of the most prominent eye signs was fixation instability (square-wave jerks, SWJ.). Besides SWJ the patients showed various combinations of cerebellar, vestibular and brain-stem oculomotor signs. Our patients did not comprise a homogeneous group with regard to their oculomotor findings. There was no correlation between the severity of any of the so-called cerebellar oculomotor disturbances and the number of SWJ. We tried to correlate the extent of oculomotor disturbances with floccular atrophy and atrophy of the dorsal vermis on MRI in seven of the patients. None of the oculomotor features (including SWJ) correlated with flocculus or dorsal vermis size. Furthermore, floccular and vermal measurements on MRI were normal. Accordingly, we think it unlikely that the oculomotor disturbances, including SWJ, are attributable to cerebellar pathology per se. 相似文献
993.
Clinically, phenol is used often as a neurolytic agent to treat pain and spasticity. The purpose of this study was to examine the time course of denervation and recovery in several hindlimb muscles following application of a 5% aqueous solution of phenol to the sciatic nerve. Phenol was applied to the sciatic nerve of adult female rats either by intraneural or perineural injection. Axonal degeneration was evident within the sciatic nerve 2 days following phenol application, although variable amounts of damage were observed. By 2 weeks, the soleus and tibialis anterior had atrophied to 63% and 51% of control. Reinnervation of hindlimb muscles occurred between 2 and 4 weeks following the nerve block. Following denervation, the soleus became slower in that all of the fibers expressed the slow myosin heavy chain (MHC). At 5 months, maximum tension of the soleus was 74% of control and the muscle consisted of more fast fibers on average, some of which expressed IIx MHC. These data suggest that 5% phenol causes an injury to the nerve that is more severe than a crush injury, and that reinnervation of denervated muscles may be by motoneurons other than those that originally innervated the muscles. © 1996 John Wiley & Sons, Inc. 相似文献
994.
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997.
Zhen-yu Wu Laurent P. Rivory Michael S. Roberts 《Journal of pharmacokinetics and pharmacodynamics》1993,21(6):653-688
Distribution of Evans Blue (EB), sucrose, and water into the isolated perfused rat hindlimb was studied under various conditions using the multiple indicator dilution (MID) technique. Statistical moment analyses of the outflow profiles for the EB, sucrose, and water were used to define the vascular, extravascular, and total water spaces, respectively. The varied perfusion conditions included albumin content (2, 4.7, and 7%), temperature (25, 37, and 42 C), perfusate flow rate (2, 4, 8, and 12 ml/min) and the presence/absence of red blood cells. The range of studies undertaken were chosen to represent the variety of conditions used in the preparation of both isolated animal and human limbs, the latter being particularly important in cytotoxic therapy for recurrent malignant melanoma. The distribution volumes of EB, sucrose, and water were dependent on the flow rate and the albumin content of perfusate. The normalized variances (CV
2
) of the markers were of the following order: sucrose (2.18) > water (1.58) > EB (0.68), indicating that some disequilibrium occurs during the capillary exchange of water and sucrose. It is suggested that a Krebs-Henseleit buffer containing 2% BSA is a suitable perfusate for most studies of the isolated rat hindlimb perfusion. The effect of albumin concentration manifests itself only at higher flows.We acknowledge the support of the National Heart Foundation (Queensland) and the Mayne Bequest Foundation. This study was conducted while the investigator (Z.Y. Wu) was in receipt of a WHO Research Training Grant. Professor M. S. Roberts also acknowledges the support of the Queensland and Northern New South Wales Lions Kidney & Medical Research Foundation. 相似文献
998.
Kenneth W. Locke Robert W. Dunn John W. Hubbard Cheri L. Vanselous Michael Cornfeldt Stuart Fielding Joseph T. Strupczewski 《Drug development research》1990,19(3):239-256
HP 818 (1-benzoyl-6-fluoro-3-(1-methyl-4-piperidinyl)-1H-indazole) exhibits the profile of a potent nonnarcotic analgesic with neuroleptic properties. HP 818 blocks the effects of chemical (phenylquinone), pressure (tail clip), and radiant heat (tail flick) painful stimuli in mice (ED50 values of 0.3, 1.2, and 4.1 mg/kg s.c., respectively). This compound displays antinociceptive activity by the subcutaneous, oral, and intravenous routes of administration. It is also effective in the shock titration assay in squirrel monkeys and in a model of surgically induced pain. The rank order of potency of HP 818 and several other standard compounds in these tests for analgesia was Innovar > fentanyl > HP 818 > codeine > droperidol. In addition to its antinociceptive effects, HP 818 possesses neuroleptic properties. It is active in the climbing mouse, pole climb avoidance, and intracranial self-stimulation assays (ED50 values of 1.8, 1.7, and 2.5 mg/kg i.p., respectively). Moreover, HP 818 inhibits amphetamine- and apomorphine-induced stereotypy, indicative of D2-dopaminergic blocking properties. HP 818, unlike typical neuroleptic agents, does not induce supersensitivity to the effects of apomorphine when administered chronically in mice. In contrast to the clinical standard neuroleptanalgesic Innovar, HP 818 (1.0–3.0 mg/kg i.v.) produces no significant cardiovascular or respiratory changes in the anesthetized dog. Thus, HP 818 is potentially an effective presurgical medication due to its nonnarcotic analgesic activity and sedative neuroleptic effects, along with its lack of limiting cardiorespiratory side effects. 相似文献
999.
1000.
A method for rapidly producing velocity images is presented. This sequence combines a modified bipolar gradient pulse to magnitude encode the velocity with the rotating ultra-fast imaging sequence (RUFIS) to image the encoded spins. Velocity encoding is done in 3 msec, and RUFIS acquires 32 projections in 8 msec. The method is applied to turbulent jets associated with a 75% stenosis in a 15-mm inner diameter glass pipe. Data is acquired upstream and downstream from the stenosis for Reynolds numbers from 560 to 3750. In addition, a robust method of reconstructing the unobserved short time region of a free induction decay is presented and incorporated into the image processing. 相似文献