高分辨率CT对颞部疾病的检查价值

目的：探讨高分辨率CT（HRCT）对颞部疾病的检查价值。方法：对43例颞部疾病患者行常规CT和高分辨率CT（HRCT）检查所获图像对比分析，并讨论HRCT的检查技术和图像后处理。结果：HRCT对病变的显示率及病变引起骨质破坏的程度，病变边缘，轮廓的显示均明显优于常规CT，尤其能清楚显示常规CT难以显示的中耳及内耳的细微结构，结论：高分辨率CT是颞部疾病的首选检查方法，使用高分辨率CT对颞部疾病的检查给临床提供更多，更准确的诊断信息。     

Prevention of Bone Loss by Clodronate in Early Postmenopausal Women with Vertebral Osteopenia: A Dose-Finding Study

This double-masked, placebo-controlled study was undertaken to determine the efficacy and safety of oral clodronate in the prevention of bone loss in early postmenopausal women with vertebral osteopenia. Altogether 610 women with a mean age of 53 years were recruited for the study. They were 1–5 years postmenopausal and their lumbar spine bone mineral density (BMD) was at least 1 standard deviation below the mean of premenopausal women (T-score ≤−1). The subjects were randomized into five study groups to receive either placebo, clodronate 65 mg, 400 mg or 800 mg daily, or intermittent clodronate in 3 month cycles with 400 mg daily for 15 days followed with no treatment for 75 days for 3 years. One hundred and eighty-seven of 509 women who completed the primary study continued in the extension study of 2 years in which previous placebo users were switched to clodronate 800 mg daily, while previous users of 400 mg or 800 mg of clodronate used either placebo or 800 mg of clodronate daily. In the primary study clodronate was administered in the evening, and in the extension 1 h before breakfast on an empty stomach. In the primary study mean changes in lumbar spine BMD were −3.4% in the placebo group and +0.4% in 800 mg clodronate group [difference between groups at 3 years 3.8% (95% CI 2.7% to 4.9%, p<0.0001)], and in the trochanter area BMD −1.1% in the placebo group, and + 0.4% in the 800 mg clodronate group [difference between groups at 3 years 1.5% (95% CI 0.05% to 2.9%)]. During the extension study mean changes in lumbar spine BMD were +1.5% in the clodronate group and −0.2 % in the placebo group [difference between groups 1.7% (CI 0.4% to 3.0%, p = 0.010)] and in trochanter BMD were +2.5% in the clodronate group and no change in the placebo group [difference between groups 2.1% (CI 0.3% to 3.9%, p = 0.007)]. No statistically significant differences between the placebo and 800 mg clodronate groups were found in the femoral neck BMD. In the primary study the urinary excretion of type I collagen aminoterminal telopeptide (NTX) decreased by 44% (p<0.0001 compared with placebo) and that of deoxypyridinoline by 18% (p<0.0001) in the clodronate 800 mg group. In the extension study urinary NTX decreased by 51% (p<0.0001) in those who were switched to 800 mg of clodronate and increased by 67% (p<0.0001) in those who stopped using that dose. There was no difference in the frequency of gastrointestinal complaints between clodronate- and placebo-treated patients in the primary study, but they were more common among women who received clodronate in the extension phase. Clodronate in daily doses of 400–800 mg caused a slight elevation of aminotransferase levels, usually within the reference range. In bone biopsies no defect in mineralization was found. In conclusion, clodronate in a daily dose of 800 mg prevents early postmenopausal bone loss at the sites of the skeleton in which cancellous bone predominates. It effectively reduces bone resorption and bone turnover rate. Antifracture efficacy of clodronate remains to be established by prospective, placebo-controlled trials. Received: 4 March 2002 / Accepted: 9 July 2002     

Influence of Lung Aeration on Pulmonary Concentrations of Nebulized and Intravenous Amikacin in Ventilated Piglets with Severe Bronchopneumonia

Background: Pulmonary concentrations of aminoglycosides administered intravenously are usually low in the infected lung parenchyma. Nebulization represents an alternative to increase pulmonary concentrations, although the obstruction of bronchioles by purulent plugs may impair lung deposition by decreasing lung aeration.

Methods: An experimental bronchopneumonia was induced in anesthetized piglets by inoculating lower lobes with a suspension of 106 cfu/ml Escherichia coli. After 24 h of mechanical ventilation, 7 animals received two intravenous injections of 15 mg/kg amikacin, and 11 animals received two nebulizations of 40 mg/kg amikacin at 24-h intervals. One hour following the second administration, animals were killed, and multiple lung specimens were sampled for assessing amikacin pulmonary concentrations and quantifying lung aeration on histologic sections.

Results: Thirty-eight percent of the nebulized amikacin (15 mg/kg) reached the tracheobronchial tree. Amikacin pulmonary concentrations were always higher after nebulization than after intravenous administration, decreased with the extension of parenchymal infection, and were significantly influenced by lung aeration: 197 +/- 165 versus 6 +/- 5 [mu]g/g in lung segments with focal bronchopneumonia (P = 0.03), 40 +/- 62 versus 5 +/- 3 [mu]g/g in lung segments with confluent bronchopneumonia (P = 0.001), 18 +/- 7 versus 7 +/- 4 [mu]g/g in lung segments with lung aeration of 30% or less, and 65 +/- 9 versus 2 +/- 3 [mu]g/g in lung segments with lung aeration of 50% or more.