双黄连滴丸的主要药效学研究

目的：评价双黄连滴丸的主要药效,为临床合理使用提供参考。方法：解热试验、抗炎试验、抗菌试验。结果：双黄连滴丸口服灌胃给药剂量在10和3g/kg（含生药）时,对细菌内毒素引起的家兔体温升高具有良好的降解作用;口服灌胃给药剂量在20和6g/kg（含生药）时,能显著抑制腹腔注射醋酸（HAC）所致小鼠腹腔毛细血管通透性的增高和二甲苯所致的小鼠耳肿胀（P＜0．01）;能保护由腹腔射金黄色葡萄球菌引起的动物死亡;体外抗菌试验表明对金黄色葡萄球菌、流感杆菌、B型链球菌具有较好的抑菌作用（最低抑制菌浓度分别为40,40和160mg/ml含生药）。结论：双黄连滴丸具有解热、抗炎、抗菌作用。     

MR fluoroscopy: initial clinical studies

Magnetic resonance (MR) fluoroscopy is a method for high-speed MR image acquisition with the goals of short acquisition time per image (500 msec or less), high image rate (10 images or more per second), and high-speed image reconstruction (150 msec or less from data acquisition to image display). The authors present their results with the first two goals in volunteers. MR fluoroscopic image data were acquired with a limited flip angle pulse sequence with reduced repetition times (TRs) and fewer phase encodings used per image. The sequence was applied continuously, and images were formed by updating one set of data with data from the most recently taken measurements. Sample head images were generated with TR/echo times as small as 11/5.5 msec and 48 phase encodings for a total acquisition time of about 500 msec. Images were acquired while the volunteer flexed his head. Artifacts from the motion became less evident on images as progressively shorter acquisition times were used.     

Complications of automatic implantable cardioverter defibrillators: radiographic, CT, and echocardiographic evaluation

Automatic implantable cardioverter defibrillators (AICDs) were studied in three groups: (a) Serial radiographs were reviewed in 51 clinic patients. Twenty of 96 (21%) AICD patches distorted with time. (b) Thirty-six postoperative computed tomographic (CT) scans of asymptomatic patients revealed that pericardial fluid collections were frequent during the month after surgery but rare beyond that. Echocardiography was insensitive for these collections. CT also demonstrated dense fibrosis around some distorted patches, months after surgery. (c) Five other patients with pericardial infection had distorted patches, and the four studied with CT had fluid beneath their patches. (d) A case of constrictive pericarditis had distorted patches but was not diagnosed with CT. The authors conclude that distorted patches may indicate postoperative complications and that CT is the imaging modality of choice.     

Platelet membrane microparticles in blood bank fresh frozen plasma and cryoprecipitate

Cryoprecipitate has been demonstrated to correct the bleeding abnormality of patients with some congenital (storage pool disease) and acquired (uremia) platelet abnormalities, but the reason for this effect is unknown. We found significant platelet contamination in plasma harvested to prepare fresh frozen plasma and cryoprecipitate. The platelet membrane microparticles produced by freezing and thawing of the plasma were highly concentrated in cryoprecipitate and may contribute to its therapeutic effect.     

Tongue and tonsil cancer: staging with US

A prospective study on the value of ultrasound (US) for the staging of 70 cases of cancer of the tongue and tonsil was performed. A real-time, high-frequency transducer was used, and the examination was often coupled with endobuccal palpation. US did not visualize the tumor in nine of 42 cases of tongue cancer (seven stage T1 and two anterior stage T2 tumors); US accurately defined tumor size in 33 cases. The degree of in-depth extension and the location with respect to the median line (only four false results) were evaluated correctly. With regard to 28 tonsil cancers, US depicted extension from the tonsillar fossa to the tongue in all cases but one (13 of 14 cases). US is valuable for the detection of cervical lymph nodes associated with both tongue and tonsil tumors and is a safe and helpful technique for the follow-up of medium-size lesions. The major limitations of US include the nonvisualization of superficial lesions, reduced accuracy for evaluation of the extension of large tumors, and analysis of posterior pharyngeal extension.     

Mechanical model testing of rebreathing potential in infant bedding materials

Rebreathing of expired air may be a lethal hazard for prone sleeping infants. This paper describes a mechanical model to simulate infant breathing, and examines the effects of bedding on exhaled air retention. Under simulated rebreathing conditions, the model allows the monitoring of raised carbon dioxide (CO2) inside an artificial lung-trachea system. Resulting levels of CO2 (although probably exaggerated in the mechanical model compared with an infant, due to the model's fixed breathing rate and volume) suggest that common bedding materials vary widely in inherent rebreathing potential. In face down tests, maximum airway CO2 ranged from less than 5% on sheets and waterproof mattresses to over 25% on sheepskins, bean bag cushions, and some pillows and comforters. Concentrations of CO2 decreased with increasing head angle of the doll, away from the face down position. Recreations of 29 infant death scenes also showed large CO2 increases on some bedding materials, suggesting these infants could have died while rebreathing.     

Surveillance in the routine management of ulcerative colitis: the predictive value of low-grade dysplasia.

Biopsies obtained at colonoscopy from 121 patients with ulcerative colitis (UC) for greater than 7 years were reviewed. Dysplasia or neoplasia was found in 27 patients (22%) after a mean of 16 years; 22 (18%) had dysplasia (all low grade), 2 had polyps, and 3 had carcinoma without prior dysplasia. Seven had dysplasia (or neoplasia) on the next examination, and another 4 after multiple negative examinations. Dysplasia preceded carcinoma in 4 (18%) of the 22 patients, and carcinoma occurred in 7 (6%) of 121 patients. The average time from the first encounter of dysplasia to the finding of carcinoma was 6.3 years, and 3 of 4 patients with negative second colonoscopies then had unremarkable examinations for 2-5 years. Dysplasia without cancer was found later in another 3. Dysplasia was found in 12 of 13 colectomy specimens, including the 3 from patients with cancer in whom no dysplasia had been found at surveillance colonoscopy. Active disease did not eliminate the capability to detect dysplasia or negate the value of surveillance for cancer when colonoscopy was conducted for routine clinical indications. Most dysplasia was detected in the rectum and sigmoid, supporting the value of interim sigmoidoscopies and biopsies during routine management of UC. Compliance for surveillance was diminished when the patient was asymptomatic, thereby increasing the risk of cancer. Low-grade dysplasia, like high-grade dysplasia, is predictive of future carcinoma and warrants careful follow-up. A "negative" second examination is no basis for a sense of security or relaxation of vigilance.