Acoustic neuromas: Gd-DTPA enhancement in MR imaging

Magnetic resonance (MR) imaging examinations were performed in ten patients with 12 acoustic neuromas before and after intravenous administration of 0.1 mmol/kg body weight gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). The degree of enhancement was greatest with the inversion recovery sequence 1,500/500/44 (repetition time [TR]/inversion time/echo delay time [TE]), followed by spin-echo (SE) 544/44 (TR/TE) sequences, then by SE 1,500/44 and SE 1,500/80 sequences. After enhancement there was a 50% reduction for measured T1 values, 33% for T2, and no significant change for proton density. There were no toxic effects on patients. Enhanced CT scans failed to demonstrate lesions in six of 12 cases. Air-CT technique improved sensitivity in four of five cases. Enhanced MR imaging added significant clinical information in two small intracanalicular tumors and in one recurrent tumor.     

Contrast medium precipitation during abdominal CT

Abdominal computed tomography (CT) scans of 55 patients who had ingested Gastrografin (meglumine diatrizoate and diatrizoate sodium) diluted to 2% with tap water and flavored with a commercial fruit juice base were reviewed. Twenty patients (36%) demonstrated intraluminal precipitation of Gastrografin shown by focal areas of markedly increased attenuation within the gastric lumen or trapped within gastric folds. Beam-hardening artifact produced by precipitation was observed, which limited the diagnostic value of some examinations. In vitro CT scans of the same Gastrografin solution titrated with hydrochloric acid or sodium hydroxide showed that by raising the pH of the solution, precipitation was virtually eliminated. Fifty-one CT scans of the abdomen using a buffered Gastrografin solution demonstrated precipitation in only five patients. Properly buffered dilute oral Gastrografin solutions should significantly decrease the prevalence of precipitation during abdominal CT examinations.     

高剂量美罗培南在肺炎囊性纤维化病人体内的药物动力学

目的 研究美罗培南在肺炎囊性纤维化病人体内的药物动力学.方法6例成年肺炎囊性纤维化住院病人,静脉滴注给予美罗培南2 g q8 h,用HPLC法测定血药浓度.采用3P87程序统计矩方法求算药代动力学参数.结果美罗培南的体内过程符合二室开放模型,其药物动力学参数分别为tmax=(0.574 2±0.020 7) h,cmax=(141.7±40.48) μg/ml,AUC=(148.7±23.42) μg*h*ml-1,t1/2β=(1.168±0.278) h,与常规剂量一致.结论肺炎囊性纤维化病人应用高剂量美罗培南时,具有良好的安全性和很好的临床疗效.     

紫草素抗炎及对白三烯B4生物合成的抑制作用

皮下注射紫草素(shikonin)10mg.kg^-1对小鼠巴豆油耳炎症和大鼠酵母性足肿有明显抑制作用;在白细胞体外温孵系统中,紫草素在10^-4～10^-7mol·L^-1浓度范围内可浓度依赖性地抑制LTB₄和5-HETE生物合成,其50%抑制浓度(IC₅₀)分别为6.2×10^-7mol.L^-1和2.6×1O^-7mol·L^-1。此外,还报道紫草素几个天然衍生物对LTB₄生物合成的影响。     

Simulated pulmonary nodules: detection with dual-energy digital versus conventional radiography

Performance of a prototype dual-energy digital chest radiography unit in detecting calcified and noncalcified simulated pulmonary nodules was compared with that of a highly optimized, conventional system. Nodules ranging in size (0.5, 1.0, and 1.6 cm), in number (five to 11), and in calcium content (0-25 mg) were superimposed over the lungs of a frozen, unembalmed, human chest phantom. For each technique, six observers examined 50 posteroanterior projections with different randomized nodule locations. Detection consisted of locating and assigning a level of confidence to each perceived nodular opacity. The resulting plots of the true-positive fraction versus the mean number of false-positive calls per projection indicate that for both calcified and noncalcified nodules, the digital unit performed significantly better (P less than .01).     

Comparison of phaconit rollable IOL with acrylic foldable IOL

Background: Phaconit or ultra micro incision phacoemulsification cataract surgery involves phacoemulsification through a 0.9 millimetre sleeveless phaco tip and irrigating chopper followed by implantation of a rollable intraocular lens. The procedure leads to negligible astigmatism and faster visual recovery as compared to phacoemulsification with a foldable intraocular lens.