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1.
Contrast-bolus tracking in the carotid bifurcation was accomplished using an MR angiographic technique with a 3D turbo field-echo readout (TR/TE = 6/3, flip angle = 50 degrees) modified by a keyhole scheme. Optimal visibility of the contrast bolus was achieved by digital subtraction from a reference volume. This technique reliably time-resolves the carotid arteries from the jugular veins.  相似文献   
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OBJECTIVE: This study was undertaken to analyze diffusion characteristics of normal and posttraumatic bone marrow. MATERIALS AND METHODS: Fifty consecutive patients with knee pain underwent both conventional and diffusion-weighted MR imaging (b values, 0-980 sec/mm2). Diffusion maps derived from source data were analyzed on a workstation using region-of-interest techniques. Apparent diffusion values recorded in normal marrow were compared with values recorded in abnormal posttraumatic bone marrow (square centimeters per second). RESULTS: Normal bone marrow identified in 35 patients showed minimal diffusion, with a mean value of 0.15x10(-5) cm2/sec. Bone marrow in 15 patients sustaining direct traumatic injury (21 bone bruises) showed markedly increased diffusion, with a mean value of 0.8x10(-5) cm2/sec (range, 0.4-1.3 cm2/sec). CONCLUSION: Marrow injury after trauma with trabecular damage allows increased movement or diffusion of interstitial water relative to normal marrow. The magnitude of diffusion change appears to reflect the severity of marrow injury.  相似文献   
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Adolescent study participants who engaged in a brief, family-centered intervention (the Family Check-Up, FCU) were later assessed for the intervention’s effects on high-risk sexual behavior (HRSB) in early adulthood (age 22). Participants (N?=?998 adolescents and their families) were randomly assigned to a family-centered intervention in sixth grade and were offered a gated, multilevel intervention that included (a) a school-based family resource center, (b) the FCU, and (c) more intensive, family-based treatment. All services were voluntary, but high-risk families were actively recruited into the FCU. Approximately 23 % of the intervention families engaged in the FCU and approximately 18 % engaged in more intensive treatment. Using an intent-to-treat design, we found that the direct effect of the FCU on HRSB was not significant; however, an analysis of the developmental processes indicated that intervention families demonstrated improved family relationship quality when compared to control families, which in turn resulted in lower levels of HRSB in early adulthood. Furthermore, the significant effect of family relationship quality on HRSB was mediated by differences in parental monitoring and early sexual activity, and these effects varied as a function of gender and ethnicity. Indirect effects of the FCU on HRSB were significant via multiple different pathways. The implications of these findings for enhancing the impact of family-centered interventions are discussed.  相似文献   
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In this study, porcine carotid arteries were subjected to balloon overstretch injury followed by local delivery of paramagnetic nanoparticles targeted to alphavbeta3-integrin expressed by smooth muscle cells or collagen III within the extracellular matrix. Carotid T1-weighted angiography and vascular imaging was performed at 1.5T. While MR angiograms were indistinguishable between control and targeted vessel segments, alphavbeta3-integrin-and collagen Ill-targeted nanoparticles spatially delineated patterns and volumes of stretch injury. In conclusion, MR molecular imaging with alphavbeta3-integrin or collagen Ill-targeted nanoparticles enables the non-invasive, three-dimensional characterization of arterial pathology unanticipated from routine angiography.  相似文献   
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Intensive care nursing allocation seemingly has been a negotiated solution to a never ending battle: an arbitrary nursing/patient ratio. To correct this deficit, a prospective study was proposed to quantitate the time duration of sufficient intensive care to match the severity of illness. A comprehensive list of all nursing actions was compiled and timed. Thereafter, frequencies were observed according to global classifications: serious, critical, or crisis. A simple classification system separates the hourly requirement: serious = 2:1 patient/nurse ratio, critical = 1.0:0.75 full time nursing, and crisis = 1.0:1.2 patient/nurse ratio (or single nurse requires assistance). The increased requirements are created by increased need for ICU skills: vital signs = 1 hour for serious patients, 4 hours for critical, and a maximum of 10 hours for crisis patients (90% crisis patients has pulmonary artery and arterial catheters). Other categories of increased nursing time reflect ventilatory support, increased number of continuous and intermittent medications, etc. Global assessment (serious, critical, or crisis patient status) can be quantitated in terms of nursing hours actually required. Objective, rational, and variable patient/nurse ratios can be easily and accurately achieved in this manner. Staffing requirements and allocation of positions can be objectively quantitated.  相似文献   
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Plastic bronchitis (PB) is a rare disease that often occurs in patients with congenital heart disease (CHD) who have undergone staged single-ventricle palliation. It is characterized by the formation of rubbery “casts” in the airways. PB treatment frequently includes inhaled tissue plasminogen activator (tPA). However, the efficacy of tPA to reduce cast burden is unknown. This is further complicated by our lack of knowledge of cast composition. We obtained spontaneously expectorated PB casts from children (n = 4) with CHD and one adult patient with idiopathic PB. Pathological assessment was made from paraffin-preserved samples. Casts were treated with phosphate-buffered saline (PBS) or tPA. Cast response to tPA was assessed by changes in cast weight and the production of fibrin d-dimer. Independent of dose, tPA reduced cast weight compared with PBS-treatment (P = 0.001) and increased d-dimer levels. Histological staining showed that PB casts from all patients were composed of fibrin and contained notable numbers of lymphocytes. Cast composition did not change over time. Collectively, these data support that in our PB patients, casts are composed of fibrin and are responsive to tPA treatment. This makes inhaled tPA a potentially viable option for symptomatic relief of PB while we work to unravel the complexity of PB pathogenesis.  相似文献   
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The stigma and embarrassment of hirsutism and the lack of public knowledge regarding effective therapy prevent some women from seeking treatment. Heightened physician awareness and a simple, practical approach to the hirsute patient allow adequate assessment and therapeutic recommendations. Decreased hair growth, a return to normal menstrual cycling, and lowered risk of endometrial cancer can be achieved by pharmacologic therapy with few serious side effects. Treatment has a significant effect on both physical and mental well-being and can produce a remarkable change in a patient who has suffered embarrassment for many years.  相似文献   
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