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Childhood sarcoidosis is a rare disorder with protean manifestations. The case of a child with prolonged fever, hepatosplenomegaly, pancytopenia, and systemic necrotizing vasculitis manifesting as fever, rash and skin infarctions, digital pregangrene, and foot drop is reported. This is the first case of systemic necrotizing vasculitis reported in sarcoidosis. The fulminant course of the disease required treatment with intravenous pulsed cyclophosphamide and high doses of corticosteroids. The spectrum of vasculitis in childhood and adult sarcoidosis is reviewed.  相似文献   
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We have obtained multislice magnetic resonance (MR) images of the eye and calculated ocular dimensions along the three cardinal axes: antero-posterior (A-P), equatorial, and vertical. We found no difference in the shape of hyperopic (average refractive error: +3.72 D) and emmetropic eyes, both of which had an equatorial diameter longer than the A-P and vertical diameters. Myopic eyes (average refractive error: -6.54 D) were larger than hyperopic eyes, and most had the same spheroelliptical shape as that of the emmetropic and hyperopic eyes. The results suggest that during myopic progression an overall enlargement or a radial volume expansion has occurred.  相似文献   
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Trisomy 8 and, less commonly tetrasomy 8, are karyotypic aberrations found in myeloid malignancies. We describe a unique case of acute myeloid leukemia with partial pentasomy 8 resulting from duplication of isochromosome 8q, and discuss its possible roles in leukemogenesis.  相似文献   
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Understanding the relationship between fMRI signal changes and activated cortex is paramount to successful mapping of neuronal activity. To this end, the relative extravascular and intravascular contribution to fMRI signal change from capillaries (localized), venules (less localized) and macrovessels (remote, draining veins) must be determined. In this work, the authors assessed both the extravascular and intravascular contribution to blood oxygenation level-dependent gradient echo signal change at 1.5 T by using a Monte Carlo model for susceptibility-based contrast in conjunction with a physiological model for neuronal activation-induced changes in oxygenation and vascular volume fraction. The authors compared our Model results with experimental fMRI signal changes with and without velocity sensitization via bipolar gradients to null the intravascular signal. The model and experimental results are in agreement and suggest that the intravascular spins account for the majority of fMRI signal change on T2*-weighted images at 1.5 T.  相似文献   
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Transcutaneous oximetry measurements were performed on 25 limbs in 25 patients with clinical and radiographic nonunion, and compared with data obtained from patients with healed tibia fractures and a control group of nonfractured extremities. A technique of "stress testing" vascular inflow patterns by temporary occlusion of arterial inflow was utilized to accentuate differences in perfusion not apparent at rest between normal limbs and those with inflow impairment. Changes in postocclusive hyperemic response were monitored by changes in transcutaneous oxygen detected by sensors placed over the dorsum of the foot, at the fracture site, over the anterior compartment, and at the chest. No statistically significant differences were found between the control group and the group of united tibia fractures. Analysis of results using the unpaired Student's t-test demonstrated statistically significant differences between the control and nonunion groups at each limb site tested (p less than 0.05). The prolonged oxygen recovery time values found in more than half the limbs with nonunion are consistent with the presence of impaired oxygenation following physiologic stress. The impairment of oxygenation appears to be on a perfusion basis and reflects the limited capacity of many limbs with tibial nonunion to respond to experimental ischemia with immediate compensatory hyperemia. Clinical relevance: This technique is a feasible method for serially assessing the regional oxygenation of a limb, and substantiates ischemia as a possible factor in the genesis of tibial nonunion.  相似文献   
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Trisomy 22 is an uncommon chromosomal abnormality in acute myeloid leukemia. Recent studies, however, have shown an association between trisomy 22 and acute myeloid leukemia with a monocytic component, and in particular, acute myelomonocytic leukemia with marrow eosinophilia. Furthermore, it has also been suggested that trisomy 22 was in fact only a secondary chromosomal change occurring in acute myeloid leukemia with inv(16). In this report, we analyze the morphological, cytogenetic, and molecular findings of three cases of acute myeloid leukemia with trisomy 22 but without cytogenetic evidence of inv(16). The results indicate a consistent association between trisomy 22 and inv(16), the latter being cytogenetically cryptic in some cases. This finding is of potential diagnostic and therapeutic significance.  相似文献   
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