唐古特大黄提取物不同成分泻下作用的比较研究

目的：研究唐古特大黄提取物不同成分的泻下作用。方法：采用炭末推进方法、酚红排空方法进行肠推进实验,观察大黄提取物各成分(15 g·kg^-1)对小鼠小肠推进和肠水分吸收、大鼠大肠运动的影响。结果：唐古特大黄提取物不同成分与对照组相比,对小鼠小肠推进和肠水分吸收、大肠推进作用均有显著性差异(P<0.01)；与大黄水煎液、醇提液相比,泻下活性存在一些差异。结论：唐古特大黄提取物不同成分均有显著的泻下作用,但与大黄水煎液和醇提液相比有一些差异。     

Decellularized dermis in combination with cultivated keratinocytes in a short- and long-term animal experimental investigation

Decellularized human dermis as a potentially ideal scaffold for dermal substitution in severe burns was examined in a two‐staged animal experiment. In an initial step, an in vitro generated composite graft consisting of human keratinocytes and decellularized dermis (AlloDerm®) was transplanted onto nude mice in a short‐term trial (n = 20, 14 days). Subsequently, a combined one‐step grafting of full thickness wounds with both decellularized dermis (in part preincubated with fibroblasts) and cultivated autologous keratinocytes as a cell suspension in fibrin glue was done in a long‐term porcine animal model (n = 10, 6 months). In both series, macroscopic wound healing was evaluated by planimetry. Histological investigations included morphological as well as immunohistochemical parameters. The short‐term study showed both successful integration of the composite grafts and reduction of wound contraction compared with the control group (epithelial grafts). The long‐term porcine study displayed reduced myofibroblast formation and contraction in the wounds that had been treated with fibroblast‐preincubated dermis. After 4 weeks, a decline of the structural integrity of the dermal matrix could be noticed. The utility of decellularized dermis as template for both dermal reconstitution and keratinocyte delivery vehicle was shown. The closure of full thickness wounds by a single‐step combination of an autologous keratinocyte fibrin sealant suspension and acellular dermis in a pig animal model could be shown. Incorporation of fibroblasts led to reduced wound contraction but could not prevent the loss of dermal integrity. The engineered ‘skin’ remained viable and stable over a period of 6 months.     

Medical students' encounters with the cadaver: A poetic response

For the past four years, the Human Values in Medicine program at the Northeastern Ohio Universities College of Medicine has sponsored the William Carlos Williams Poetry Competition for medical students (U. S. only). With over 1700 entries from hundreds of students representing nearly every medical school in the U.S., the competition has been highly successful. The pervasive themes expressed in the poetry have included personal experiences and relationships outside of medicine, the medical school experience, nature, and the physician-patient encounter. Within this last theme, I found dozens of poems on the medical student's encounter with the cadaver.

This paper examines what the medical student-poets wrote about that experience. The texts of the twenty poems each fell into one of the following categories: the attempt of the student to know the cadaver as a person, the medical secrets students discovered through dissection, and the intimate relationship between student and cadaver.

Discussion and excerpts from the poetry which illuminate each category are found in the following narrative.     

Pediatric patients with achondroplasia: CT evaluation of the craniocervical junction

Twenty-six patients (4 months to 6 years old) with achondroplasia complicated by sleep apnea and/or other neurologic manifestations underwent plain computed tomography (CT) of the craniocervical junction; six also underwent CT myelography. For objectification, multiplanar reconstruction was used to complement axial plane measurements by providing coronal and sagittal measurements; multiplanar reconstruction also improved perception of the longitudinal relationships between the brain stem and subarachnoid space. A narrow subarachnoid space was found in all 26 patients; marked cord compression was present in nine, six of whom underwent CT myelography. These six had marked focal obliteration of the subarachnoid space on both plain CT and CT myelography. Since the subarachnoid space immediately above and below the craniocervical junction is normally capacious, when marked constriction was present, no additional information could have been gained from CT myelography. Thus, plain CT was shown to be sufficient for surgical planning (suboccipital decompression) in nine patients with cord compression due to achondroplasia.     

Does the perception of downloading speed influence the evaluation of web-based lectures?

Medical schools put little emphasis upon education on public health, even though public health has played an important role in this century. One way to harness its benefit in order to improve global health in the 21st century is to globally share lectures on public health through the Internet. We have developed the Supercourse comprising of web-based learning modules on epidemiology in a standardized format with the size of each web page less than 10 kilobytes. A cross-sectional observational study was conducted to investigate the association of the perception of the access speed to Web-based lectures by teachers with their perception of lecture quality. There were 223 teachers who rated the lectures: 72% were from North America or Western Europe, 40% had taught epidemiology, and 14% reported that the speed of access was slow. Odds ratio of above-average rating among those who reported that the speed of access was fast relative to those who reported that the speed of access was slow was 4.25 (2.03-8.91; P = 0.001). The odds ratios were similar and significant after taking into account several other factors, including the variation of rating across lectures, region, and experiences in teaching epidemiology. The results indicate that the perception of the quality of Web-based lectures is related to the speed of access to a web page. The speed of access may be as important, if not more important, as the content itself. This suggests that, to share educational materials on the Web globally for teachers, one must consider not only the content, but also how people at local sites gain access to the Internet.     

Subtle gastric abnormalities in a canine model: detection with low-dose imaging with storage phosphors and its equivalence to conventional radiography

The authors compared low-dose (32% of standard exposure) storage phosphor digital imaging (system resolution: 0.2-mm pixels, 10 bits) with isovoltage 75-kVp conventional radiography (standard exposure) in the detection of subtle simulated gastric abnormalities by using air contrast barium studies. Subtle simulated abnormalities (3-7-mm polyps, 4-15-mm ulcer craters, 4-11-mm-diameter edema, and 11-12-mm linear ulcers) were produced in resected canine stomachs. Receiver operating characteristic analysis of 1,800 observations by six readers indicated that the digital images with and without high-frequency edge enhancement were equivalent to conventional radiographs (mean receiver operating characteristic areas [+/- standard deviation]: 0.76 +/- 0.06, 0.78 +/- 0.04, and 0.77 +/- 0.04, respectively). The accuracy of the diagnosis was equivalent for all three modalities. The following mean accuracies of negative and positive responses, respectively, for unenhanced digital, edge-enhanced digital, and conventional images were determined: 0.71 +/- 0.05 and 0.41 +/- 0.07, 0.71 +/- 0.04 and 0.51 +/- 0.09, and 0.68 +/- 0.04 and 0.43 +/- 0.05. It was concluded that low-dose storage phosphor air-contrast barium studies were equivalent to conventional radiography in the detection of subtle gastric abnormalities.