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991.
BACKGROUND: There are few reports on maternal cerebral circulation during pregnancy. Using the hypothesis that cerebral blood flow resistance decreases progressively with advancing gestational age (GA) as a consequence of estrogenic effects on the vascular system during pregnancy, we calculated the pulsatility index (PI) and the mean velocity (MV) of the maternal right internal carotid artery (ICA) in order to build fitted reference centiles. METHODS: A total of 315 pregnant women with a single fetus were studied at 20-42 weeks' gestation. The patients had uncomplicated singleton pregnancies and were without any known fetal or maternal risk factors. Duplex color ultrasound with a pulsed Doppler scanner (7.5 MHz) was used to determine the PI and MV of the maternal ICA. RESULTS: Among the 315 healthy pregnant women, the PI of maternal ICA decreased progressively with advancing GA, PI50th = Exp (0.3124-0.0084 x GA), (p = 0.0003), during the second half of pregnancy. The predicted 50th percentile PI values of the ICA decreased from 1.117 (5th% = 0.755, 95th% = 1.654) at 24 weeks' gestation to 0.917 (5th% = 0.659, 95th% = 1.448) at 40 weeks' gestation. The MV of the maternal ICA also decreased progressively with advancing GA, MV50th = Exp (3.855-0.0093 x GA), (p = 0.0005), during the second half of pregnancy. The predicted 50th percentile MV values in the ICA decreased from 37.811 cm/sec (5th% = 24.177 cm/sec, 95th% = 59.138 cm/sec) at 24 weeks' gestation to 32.591 cm/sec (5th% = 20.818 cm/sec, 95th% = 51.021 cm/sec) at 40 weeks' gestation. CONCLUSIONS: Both the PI and MV of the maternal ICA decreased with GA during the second half of normal pregnancy as a result of intracerebral vessel dilatation. 相似文献
992.
The piggyBac (IFP2) short inverted terminal repeat transposable element from the cabbage looper Trichoplusia ni was tested for gene transfer vector function as part of a bipartite vector-helper system in the Mediterranean fruit fly Ceratitis capitata. A piggyBac vector marked with the medfly white gene was tested with a normally regulated piggyBac transposase helper at two different concentrations in a white eye host strain. Both experiments yielded transformants at an approximate frequency of 3-5%, with a total of six lines isolated having pigmented eyes with various levels of coloration. G1 transformant siblings from each line shared at least one common integration, with several sublines having an additional second integration. For the first transformant line isolated, two integrations were determined to be stable for 15 generations. For five of the lines, a piggyBac-mediated transposition was verified by sequencing the insertion site junctions isolated by inverse PCR that identified a characteristic piggyBac TTAA target site duplication. The efficient and stable transformation of the medfly with a lepidopteran vector represents transposon function over a relatively large evolutionary distance and suggests that the piggyBac system will be functional in a broad range of insects. 相似文献
993.
We examined the effect of a humanized anti-glycoprotein IIb/IIIa monoclonal antibody, YM337, on thrombolysis with tissue-type plasminogen activator in a copper coil-induced coronary thrombosis model in rhesus monkeys. Fifty minutes after the formation of an occlusive thrombus, a test drug was administered by either i.v. bolus injection followed by continuous infusion (YM337, 0.25 mg/kg + 1.5 microg/kg/min) or i.v. bolus injection (aspirin, 17 mg/kg). Sixty minutes after induction of the occlusive thrombus, thrombolysis was initiated with tPA at a total dose of 0.5 mg/kg intravenously administered over 60 min, with 10% given as an initial bolus. The median time to reperfusion was significantly shortened by YM337 [saline, 60 min (n = 5); aspirin, 45 min (n = 5); YM337, 30 min (n = 5)]. The incidence of reocclusion was significantly decreased by YM337 (saline, 4/4; aspirin, 5/5; YM337, 1/5), and the median time to reocclusion was significantly prolonged by YM337 [saline, 30 min (n = 4); aspirin, 30 min (n = 5); YM337, 180 min (n = 5)]. YM337 significantly reduced the thrombus protein content at the end of experiment. ADP-induced platelet aggregation was completely inhibited by YM337. These results suggest that YM337 may be of clinical value as an adjunctive agent in thrombolytic therapy for patients with acute myocardial infarction. 相似文献
994.
Review of moderate alcohol consumption and reduced risk of coronary heart disease: is the effect due to beer, wine, or spirits 总被引:1,自引:0,他引:1
OBJECTIVES: To review the effect of specific types of alcoholic drink on coronary risk. DESIGN: Systematic review of ecological, case-control, and cohort studies in which specific associations were available for consumption of beer, wine, and spirits and risk of coronary heart disease. SUBJECTS: 12 ecological, three case-control, and 10 separate prospective cohort studies. MAIN OUTCOME MEASURES: Alcohol consumption and relative risk of morbidity and mortality from coronary heart disease. RESULTS: Most ecological studies suggested that wine was more effective in reducing risk of mortality from heart disease than beer or spirits. Taken together, the three case-control studies did not suggest that one type of drink was more cardioprotective than the others. Of the 10 prospective cohort studies, four found a significant inverse association between risk of heart disease and moderate wine drinking, four found an association for beer, and four for spirits. CONCLUSIONS: Results from observational studies, where alcohol consumption can be linked directly to an individual's risk of coronary heart disease, provide strong evidence that all alcoholic drinks are linked with lower risk. Thus, a substantial portion of the benefit is from alcohol rather than other components of each type of drink. 相似文献
995.
This brief review summarizes the physiology and pharmacology of eicosanoids and describes how they have been tested for possible application in liver disease and transplantation. The objective is to trace the stepwise application from the laboratory to the bedside. Although many questions remain to be answered, the observations summarized in this article have opened up new and potentially rewarding prospects in application to liver disease. 相似文献
996.
SG Rijpkema MJ Molkenboer LM Schouls F Jongejan JF Schellekens 《Canadian Metallurgical Quarterly》1995,33(12):3091-3095
We developed a rapid and reliable method for the identification Borrelia burgdorferi sensu lato species in ticks. We used the DNA sequence polymorphism of the spacer region between 5S and 23S rRNA genes, which has been shown to be able to discriminate between eight genomic groups of B. burgdorferi sensu lato (D. Postic, M. Assous, P. A. D. Grimont, and G. Baranton, Int. J. Syst. Bacteriol. 44:743-752, 1994). Spacer DNA was amplified by PCR and was then hybridized to five membrane-bound oligonucleotides. The oligonucleotides were specific for B. burgdorferi sensu stricto, Borrelia garinii, Borrelia afzelii, and group VS116. A probe which reacted with all genomic groups of B. burgdorferi sensu lato was also used. Ninety-six ticks collected in the field were destructed by bead beating, and the supernatant was used directly in a PCR. B. burgdorferi sensu lato DNA was detected in 6 of 57 adult ticks (11%) and 9 of 39 nymphs (23%). B. garinii was found in three nymphs and four adults, three nymphs carried B. afzelii, and one adult and one nymph carried group VS116. Double infections with B. afzelii and group VS116 were found in two nymphs and one adult. Thus, our method can simultaneously identify three genomic groups of B. burgdorferi sensu lato in ticks collected in the field. This technique provides new ways to study the association of genomic groups present in ticks and the risk of Lyme borreliosis. 相似文献
997.
RM Siegel DA Martin L Zheng SY Ng J Bertin J Cohen MJ Lenardo 《Canadian Metallurgical Quarterly》1998,141(5):1243-1253
The death-effector domain (DED) is a critical protein interaction domain that recruits caspases into complexes with members of the TNF-receptor superfamily. Apoptosis can also be induced by expressing certain DED-containing proteins without surface receptor cross-linking. Using Green Fluorescent Protein to examine DED-containing proteins in living cells, we show that these proteins cause apoptosis by forming novel cytoplasmic filaments that recruit and activate pro-caspase zymogens. Formation of these filaments, which we term death-effector filaments, was blocked by coexpression of viral antiapoptotic DED-containing proteins, but not by bcl-2 family proteins. Thus, formation of death-effector filaments allows a regulated intracellular assembly of apoptosis-signaling complexes that can initiate or amplify apoptotic stimuli independently of receptors at the plasma membrane. 相似文献
998.
999.
1000.
MJ Hickey AC Issekutz PH Reinhardt RN Fedorak P Kubes 《Canadian Metallurgical Quarterly》1998,83(11):1124-1131
The objective of this study was to determine whether endogenous IL-10 is capable of regulating hemodynamic parameters, leukocyte recruitment, and microvascular permeability in response to endotoxin. Intravital microscopy was used to examine hemodynamic parameters, leukocyte rolling and adhesion, and microvascular permeability in cremasteric postcapillary venules in wild-type mice and in IL-10-deficient (IL-10(-/-)) mice exposed to lipopolysaccharide (LPS). Doses of LPS (3 or 30 microg/kg, IV), which did not reduce blood pressure and minimally altered microvascular hemodynamic factors in wild-type mice, caused significant reductions in these parameters in IL-10(-/-) mice, demonstrating at least a 10-fold increased sensitivity in IL-10(-/-) mice to LPS-induced hemodynamic alterations. Furthermore, in response to LPS (30 microg/kg, IV), leukocyte rolling, adhesion, and fluorescein isothiocyanate-albumin extravasation were increased in the IL-10(-/-) mice. Antibody blockade experiments showed that in both types of mice, leukocyte rolling was mediated by E-selectin and P-selectin. Leukocyte accumulation into other tissues, such as lung, also was enhanced greatly in IL-10(-/-) mice. This was specific to endotoxin, because acute chemotactic stimuli including N-formyl-methionyl-leucyl-phenylalanine elicited similar responses in IL-10(-/-) and wild-type mice. These results suggest that endogenous IL-10 may be a homeostatic regulator of hemodynamic parameters, leukocyte-endothelial cell interactions, and microvascular dysfunction in response to endotoxin and provide potential mechanisms to explain the protective effect of IL-10 against LPS-induced mortality. 相似文献