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Precise and accurate inversion-recovery (PAIR) magnetic resonance (MR) measurements of T1 were obtained in eight brain regions and cerebrospinal fluid of 26 healthy volunteers. Accuracy of the technique was assessed by measuring T1 in small fluid volumes with the PAIR technique and with two independent spectroscopic techniques. The mean difference between T1 measured with PAIR and with the two spectroscopic techniques was 3.1% ± 1.3. The precision (reproducibility) of measurements with the PAIR technique was excellent. The coefficient of variation (CV) across 16 measurements in a head phantom was 2.0%, compared with a CV of 2.7% across 45 separate measurements in a single subject. The within-subject CV was 1.8% ± 0.6 in white matter and 1.4% ± 1.0 in basal ganglia. The between-subject CV in 26 healthy volunteers was 3.6% ± 0.6 in white matter and 4.1% ± 1.9 in basal ganglia. Comparison between a patient with an active recurrent brain tumor and an agematched patient with an inactive brain tumor showed that T1 was significantly elevated throughout the brain of the active-tumor patient, especially in white matter tracts, even though no tumor or edema was detected in the white matter on standard MR images. Comparisons between five brain tumor patients and four healthy volunteers of similar age showed that T1 was significantly and substantially elevated throughout the white matter tracts and in the caudate nucleus, putamen, and thalamus. These results are consistent with the hypothesis that white matter tracts are selectively vulnerable to edema and that T1 increases in white matter are a sensitive indicator of patient status or tumor aggressiveness.  相似文献   
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Proliferation of rheumatoid and control peripheral blood mononuclear cells to OKT3, phorbol myristic acid (PMA), phytohemagglutinin (PHA), tuberculin PPD and in the autologous mixed lymphocyte reaction (AMLR) was investigated. Only the responses to PPD and in the AMLR were depressed. This was not due to suppression by OKT8 lymphocytes. The proportion of antigen responsive (T4+ 4B4+) cells was normal but suppressor-inducer (T4+ 2H4+) cells were decreased. The depressed response was not completely restored by addition of recombinant interleukin-2. We propose that a basic defect in rheumatoid arthritis resides in T lymphocytes which react to self-major histocompatibility complex antigens either on their own, as in the AMLR, or as restriction elements in the presentations of soluble antigen.  相似文献   
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Child care agencies in Ohio were surveyed concerning their programs and child care workers so as to better understand factors that contribute to job stress, attrition, and satisfaction. The survey provided data regarding the population served at the agencies and the characteristics of child care workers, their services, concerns, desires, and rewards. The findings indicate that environmental variables contribute largely to perceived concern and desired changes, whereas success with children provides a prominent source of job satisfaction.  相似文献   
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The purpose of this prospective, randomized, double-blind study was to determine if the volume of a fixed milligram dose of hyperbaric tetracaine hydrochloride injected into the subarachnoid space affected the average maximal dermatomal spread of sensory anesthesia, determined by pinprick testing. One hundred two adults received spinal hyperbaric tetracaine in a volume of 2 mL, 3 mL, or 4 mL with the dose based on the patient's height. The addition of 0.2 mg of epinephrine to the anesthetic solution was allowed at the discretion of the attending anesthesiologist. A two-way analysis of variance (ANOVA) demonstrated that neither the dose selected nor the use of epinephrine affected anesthetic spread. ANOVA showed that anesthetic volume insignificantly affects the spread of sensory anesthesia. A Tukey HSD multiple comparisons test demonstrated a mean difference greater than 1 sensory dermatome between volumes of 2 mL and 4 mL, which was clinically detectable but statistically insignificant. Increasing the volume of hyperbaric spinal tetracaine solutions to improve anesthetic spread is unjustified.  相似文献   
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The need for effective infection control applies to all areas of patient care, but is often carried out on an ad hoc basis. Implementing infection control procedures as part of the nursing process will ensure this area of care is not overlooked.  相似文献   
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Small, patent cerebral aneurysms: atypical appearances at 1.5-T MR imaging   总被引:1,自引:0,他引:1  
Rolen  PB; Sze  G 《Radiology》1998,208(1):129
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