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.     

Digital radiographic imaging system with multiple-slit scanning x-ray beam: preliminary report

A digital imaging system that employs a novel scanning x-ray tube, a multiple-slit assembly (MSA), and an image intensifier (II)-TV digital system is described. Use of the MSA can increase x-ray utilization by a factor of 100 over that obtained with single-slit systems. Scatter and veiling glare can be reduced substantially by synthesizing the final image from a number of multiple-slit images, resulting in improvement in contrast sensitivity. An experimental prototype system consisted of a conventional x-ray tube and an II-TV digital system used in conjunction with mechanical scanning of the MSA. Attenuation curves measured with an aluminum stepwedge showed that scatter and veiling glare were eliminated by this approach. Reconstructed images of phantoms were superior to images obtained with conventional wide-beam exposure. Physical parameters related to design of the scanning x-ray tube and a digital system for acquiring images of the chest are discussed.     

Blood pressure independent effects of nitrendipine on cardiac structure in patients after renal transplantation

Left ventricular hypertrophy is well established as a blood pressure independent cardiovascular risk factor in patients on renal replacement therapy. The effects of antihypertensive treatment on myocardial structure and function in renal transplant recipients have been so far only rarely investigated. In a double-blind, placebo-controlled study patients were randomized to the calcium channel blocker nitrendipine or placebo if the transplanted kidney had developed a stable phase. Normotensive patients received nitrendipine 2 x 5 mg daily or placebo, hypertensive patients received 2 x 10 mg up to 2 x 20 mg nitrendipine daily or placebo. To achieve adequate blood pressure control, all patients with still elevated blood pressure on study medication received antihypertensive drugs other than calcium channels blockers. Ambulatory blood pressure recording and 2D-guided M-mode echocardiography were performed at baseline and upon completion of the study. In addition, laboratory workup (including serum creatinine and lipids) was done, and serum aldosterone, plasma renin activity, plasma angiotensin II and blood glucose levels were measured in all patients at baseline and after at least 12 months of therapy. Ambulatory blood pressure was almost identical between both groups at study baseline and follow-up. In renal transplant patients on nitrendipine, posterior wall thickness (-0.10 +/- 1.77 mm) and septal wall thickness (-0.83 +/- 2.23 mm) did not change significantly from baseline. In contrast, posterior wall thickness (0.71 +/- 0.92 mm, P < 0.01) and septal wall thickness (0.97 +/- 2.20 mm, P < 0.05) increased in patients on placebo, which differed from the observed changes on nitrendipine (ANOVA: P = 0.093 and P = 0.048, respectively). Relative wall thickness, a parameter for concentric left ventricular hypertrophy, became numerically smaller on nitrendipine therapy from 0.46 +/- 0.07 to 0.44 +/- 0.09 (-0.02 +/- 0.09, NS) but increased from 0.42 +/- 0.08 to 0.48 +/- 0.08 in the placebo arm (+0.04 +/- 0.08, P < 0.02), which was also significant between the two groups (ANOVA: P = 0.036). Endocrine parameters, lipids and blood glucose were not different between the two groups. We conclude from these data that the calcium channel blocker nitrendipine exerted beneficial effects on cardiac structure in patients after renal transplantation independent of blood pressure.      

旋光活性内酯化合物的研究:(—)MALYNGOLIDE的全合成

以己二酸为起始原料,成功地合成了有手性季碳中心的内酯化合物(—)-Mialyngolide(1),其中关键的步骤采用手性相转移催化剂进行立体选择烷基化反应,此合成路线短,总收率为10.5%。     

旋光活性内酯化合物的研究：（—）MALYNGOLIDE的全合成

以己二酸为起始原料，成功地合成了有手性季碳中心的内酯化合物（—）－Ｍｉａｌｙｎｇｏｌｉｄｅ（１），其中关键的步骤采用手性相转移催化剂进行立体选择烷基化反应，此合成路线短，总收率为１０．５％。     

A population-based study of surgery for spinal metastases. Survival rates and complications

The management of spinal metastases is palliative and aimed at improving quality of life at an acceptable risk. This population study uses administrative databases and measures survivorship and complication rates after surgery for spinal metastases. The effects of various potential predictor variables were evaluated. We identified 987 patients with a median survival for all types of cancer of 227 days. The one and three-month mortality was 9% and 29%, respectively. Increasing age, male gender and primary lung cancer were significant risk factors for death within 30 days of surgery. A preoperative neurological deficit contributed a 19% increase in mortality and a 71% increase in the risk of postoperative wound infection. We found an overall major complication rate of 27%. This information will provide patients, families and clinicians with objective data which will help in the choice of treatment and the understanding of the surgical risk and outcome.