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排序方式: 共有381条查询结果,搜索用时 46 毫秒
71.
Belz GT Wilson NS Smith CM Mount AM Carbone FR Heath WR 《European journal of immunology》2006,36(2):327-335
While naive CD8(+) T cells have been shown to require bone marrow-derived dendritic cells (DC) to initiate immunity, such a requirement for memory CD8(+) T cells has had limited assessment. By generating bone marrow chimeras that express the appropriate antigen-presenting molecules on either radiation-sensitive bone marrow-derived or radiation-resistant non-bone marrow-derived compartments, we showed that both primary and secondary immune responses to influenza virus infection of the lung were initiated in the draining LN. This required cells of bone marrow origin, most likely DC, for optimal expansion within the secondary lymphoid compartment. This was similarly the case with HSV-1 infection of the skin. As Langerhans cells are radioresistant, unlike other DC populations, these studies also demonstrate that the radiosensitive DC responsible for secondary expansion of HSV-specific memory are not Langerhans cells. 相似文献
72.
GT Terézhalmy AR Biesbrock PA Walters JM Grender RD Bartizek 《International journal of dental hygiene》2008,6(4):321-327
Abstract: Aim: To compare plaque removal efficacy of Oral‐B CrossAction (CA) used for 1 min with an American Dental Association (ADA) manual toothbrush used for 2 or 5 min in an examiner‐blind, three‐treatment, six‐period crossover study. Materials and methods: After refraining from all oral hygiene procedures for 23–25 h, subjects were randomly assigned to one of nine possible six‐period (visit) treatment sequences. Plaque was assessed at baseline (Rustogi Modified Navy Plaque Index). Post‐brushing scores were recorded after brushing with a marketed dentifrice and the assigned toothbrush for the specified duration. The same procedure was followed at each of six subsequent visits. Clinical measurements were carried out by the same examiner. Results: Forty subjects completed the study. All three treatments effectively removed plaque from the whole mouth, along the gingival margin and from approximal surfaces. Whole mouth and gingival margin plaque removal scores with CA for 1 min did not differ significantly from scores with the ADA toothbrush used for 2 min. The ADA brush used for 5 min showed significantly greater whole mouth (P < 0.001) and gingival margin (P < 0.001) plaque reduction than the two other treatments. Approximal plaque removal scores did not differ between the three treatments. Conclusions: Efficient plaque removal can be achieved after 1 min of brushing with CA. The amount of plaque removed did not differ significantly from that achieved with the ADA brush after 2 min of brushing. Greater whole mouth and gingival margin plaque removal scores were seen with the ADA brush after 5 min. 相似文献
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75.
Obstruction of the small intestine: accuracy and role of CT in diagnosis 总被引:17,自引:0,他引:17
Maglinte DD; Gage SN; Harmon BH; Kelvin FM; Hage JP; Chua GT; Ng AC; Graffis RF; Chernish SM 《Radiology》1993,188(1):61
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77.
We tested the hypothesis that differences exist in the pharmacodynamic pattern of different cardiac glycosides. We conducted a randomized, placebo-controlled study in normal volunteers and evaluated the effects of weekly increased oral dosing of digoxin (n = 10; from 0.25 to 1.0 mg/day), meproscillarin (n = 10; from 0.5 to 2.0 mg/day), and placebo (n = 5). To determine the glycoside effects, corrected electromechanical systole (QS2c) was used to measure inotropy and the PQ interval to test dromotropy. Red-green discrimination and critical flicker fusion (CFF) assessed visual functions. Subjective complaints were collected using rating lists. Both glycosides dose dependently shortened QS2c and prolonged PQ interval. PQ prolongations over +20 ms occurred in seven of 10 digoxin subjects, in two of 10 meproscillarin, and in one of five placebo. Equi-inotropic response, identified at 12 ms mean QS2c shortening, revealed the relative potency of digoxin to be 2.4 times higher than meproscillarin; this ratio increased to sevenfold for equi-effective negative dromotropic effects at 12 ms mean PQ prolongation. Each drug was associated with a dominant subjective complaint: digoxin with anergy and meproscillarin with diarrhea. Red-green discrimination was better under meproscillarin and CFF was depressed by digoxin. The results indicate that pharmacodynamic differences exist between cardiac glycosides. A differential use of various glycosides should be considered and tested clinically. 相似文献
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Cerebral venous angiomas: MR imaging 总被引:3,自引:0,他引:3
80.
Elastic properties and Windkessel function of the human aorta 总被引:3,自引:0,他引:3
Prof. Gustav G. Belz 《Cardiovascular drugs and therapy / sponsored by the International Society of Cardiovascular Pharmacotherapy》1995,9(1):73-83
Summary An understanding of the role of the aortic elastic properties indicates their relevance at several sites of cardiovascular function. Acting as an elastic buffering chamber behind the heart (the Windkessel function), the aorta and some of the proximal large vessels store about 50% of the left ventricular stroke volume during systole. In diastole, the elastic forces of the aortic wall forward this 50% of the volume to the peripheral circulation, thus creating a nearly continuous peripheral blood flow. This systolic-diastolic interplay represents theWindkessel function, which has an influence not only on the peripheral circulation but also on the heart, resulting in a reduction of left ventricular afterload and improvement in coronary blood flow and left ventricular relaxation. The elastic resistance (or stiffness), which the aorta sets against its systolic distention, increases with aging, with an increase in blood pressure, and with pathological changes such as atherosclerosis. This increased stiffness leads to an increase in systolic blood pressure and a decrease in diastolic blood pressure at any given mean pressure, an increase in systolic blood velocity, an increase in left ventricular afterload, and a decrease in subendocardial blood supply during diastole, and must be considered a major pathophysiological factor, for example, in systolic hypertension. The elastic properties of the aortic Windkessel can be assessed in vivo in humans in several ways, most easily by measuring the pulse wave velocity along the aorta. The higher this velocity, the higher the elastic resistance, that is, the stiffness. Other methods depend on assessment of the ratio between pulse pressure and aortic volume changes (P/V), which can be assessed noninvasively by ultrasonic or tomographic methods. All assessments of vessel stiffness have to take into account the direct effect of current blood pressure, and thus judgements about influences of interventions rely on an unchanged blood pressure. Alternatively, to derive the intrinsic stiffness of the aortic wall one has to correct for the effect of the blood pressure present. Recently reports about pharmacologic influences on the elastic properties of the aorta have emerged in the literature. Angiotensin-converting enzyme (ACE) inhibitors and nitric oxide (NO) donors seem to directly reduce the elastic resistance of the aorta. This effect, in addition to other effects on blood pressure and the peripheral circulation, could have major clinical relevance as an additional mechanism for unloading the left ventricle, improving coronary circulation, and reducing the pulsatile stress of the arterial system. 相似文献