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Mushroom worker's lung disease 总被引:1,自引:0,他引:1
146.
The results of Kr-81m/Tc-99m ventilation-perfusion (VP) lung scintigraphy were correlated with the results of pulmonary angiography for 74 patients suspected of having pulmonary embolism (PE). Among patients having a diagnostic scan, the sensitivity and specificity of scintigraphy were 91% and 94%, respectively. Also, 157 consecutive cases of Kr-81m/Tc-99m VP lung scintigraphy were reviewed, and the frequency of an indeterminate scan was found to be 22%. A similar frequency was found for VP scintigraphy with xenon-133. Of eight patients who had indeterminate scans due to the presence of a single VP mismatch, four were demonstrated to have PE by angiography. Kr-81m is an excellent agent for VP scanning in cases of suspected PE, offering accuracy in diagnosis as well as favorable physical properties. 相似文献
147.
Ocular MR imaging and spectroscopy: an ex vivo study 总被引:2,自引:0,他引:2
Gomori JM; Grossman RI; Shields JA; Augsburger JJ; Joseph PM; DeSimeone D 《Radiology》1986,160(1):201-205
Six eyes, freshly enucleated because of choroidal melanoma, were imaged on a 1.4-T superconducting magnetic resonance (MR) imaging system, and relaxation times were calculated for various parts of the eye. Unfixed fresh tissue samples were obtained for nuclear magnetic resonance spectroscopy (NMRS) on a variable-field (0.19-1.4 T) resistive unit. Detailed ocular anatomy was demonstrated. The NMRS relaxation times correlated with the MR imaging intensity patterns. The sensitivity of MR imaging to states of hydration provides an excellent window for appreciation of ocular anatomy. 相似文献
148.
A case of achalasia complicated by Mycobacterium fortuitum pulmonary infection and empyema is reported. This association has been documented in the medical literature. Possible mechanisms explaining this association are discussed. 相似文献
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150.
The NADPH-dependent reduction of chromium (VI), a known carcinogen, by
hepatic microsomes was very similar for all five humans examined, with an
apparent Km for chromate of 1.04-1.68 microM, and a Vmax of 10.4- 10.7
nmol/min/mg protein. Inhibitor studies indicate no role for cytochrome
P450s, but a prominent role for flavoproteins, which could include P450
reductase, flavin-containing mono-oxygenase and cytochrome b5. Relative to
anaerobic conditions, Cr(VI) reduction was inhibited only 26-37% by room
air, which indicates that human microsomal Cr(VI) reduction could still
proceed at significant rates, even in tissues with high O2 tensions.
Studies with lung microsomes from one human exhibited Vmax and Km values
that were two-thirds lower and 2.8-fold greater, respectively, than those
of hepatic microsomes from the same individual; other Cr(VI)-reducing
parameters were similar for lung and liver. Various forms of exogenous
iron, when present at 0.76-6.3 microM, markedly enhanced both liver and
lung microsomal rates and Vmax of Cr(VI) reduction, but did not
significantly alter the other Cr(VI)- reducing parameters (Km, effects of
O2 and inhibitors). These iron levels were 3.1- to 26-fold lower than the
initial Cr(VI) concentration, which suggests that iron is serving a
catalytic role. The ratio of human microsomal Cr(VI) reduction rates under
aerobic versus anaerobic conditions remained fairly constant, regardless of
iron concentration. Small increases in intracellular iron could therefore
lead to large increases in the rate and extent of microsomal Cr(VI)
reduction. Individuals that are simultaneously exposed to Cr(VI) and to
agents that increase intracellular iron could therefore be at potentially
greater risk for Cr(VI) toxicity and carcinogenicity.
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