Practice guidelines: the radiology perspective

Clinical practice guidelines have emerged as a reality for medical practitioners over the past 20 years. Although virtually all groups interested in the development of practice guidelines hope for improvements in patient care, secondary expectations vary widely among those using them. Their use in daily practice by physicians has met with resistance from barriers including concerns of “cookbook” medicine, a loss of autonomy, and increased professional liability. The recent experience of the ACR in addressing these challenges illustrates that physicians are receptive to steps perceived to mitigate the risks accompanying the use of guidelines as well as to efforts to increase their understanding of implementing guidelines in clinical practice. The experiences of other medical societies and an inventory of future trends reveal additional challenges associated with the use of practice guidelines, as third parties look to guidelines as points of reference for gauging the performance of health care providers.     

颈内动脉接近完全闭塞时的处理

目的由于卒中风险随着狭窄严重程度的增加而升高，因此认为颈内动脉（ICA）接近闭塞患者的卒中风险很高。在现有的随机试验中，还没有专门针对这种情况进行探讨，因此其处理尚存在争汶。方法：对相关文献进行系统评价。结果：对ICA接近闭塞患者的处理还存在争议：一些学者支持进行干预，而另一些学者则认为存在风险或没有益处而反对进行干预。在ICA接近闭塞的有症状患者中进行一项比较外科治疗与最佳内科治疗的多中心前瞻性随机试验似乎非常困难，因为这类研究需要大量的患者。尽管如此，基于目前的证据，似乎很难拒绝手术治疗。结论：由于目前对ICA接近闭塞患者的最佳处理方案仍存在着争议，因此需要前瞻性观察性研究以证实其在有症状和无症状人群中的患病率以及相关的卒中风险。基于目前的证据，大多数医疗中心选择手术治疗，但它相对干内科治疗的特粱尚右待证章．     

Inhibition of platelet aggregation by novel triphenylethylene analogs

The present study has evaluated the effect of some newly synthesized triphenylethylene (TPE) analogs on platelet arachidonic acid metabolism and function. All compounds tested inhibited arachidonic acid induced platelet aggregation and several were superior to aspirin in their relative potency. Introduction of a carboxyl function into the alpha-ring, which should enhance binding according to proposed structural models for cyclooxygenase inhibitors, was not found to be beneficial. Increased structural rigidity, which resulted from covalent linkage of two aromatic rings in this series, did not eliminate anti-aggregatory properties.     

Flow cytometric analysis of testicular tissue: Detection of injury and recovery

Summary DNA flow cytometry was used to examine the effects of five chemotherapeutic agents, vinblastine, cisplatinum, 5-fluorouracil, cyclophosphamide and Adriamycin, on mouse testes. Alterations in the haploid (1C), diploid (2C) and tetraploid (4C) cell compartments were assessed at 11, 29 and 56 days after giving mice a single intraperitoneal injection of each agent. Analysis of the histograms proved to be a rapid and reproducible method of monitoring injury in this animal model. Because this procedure can detect subtle testicular injuries, it is predicted that DNA histograms obtained from fine needle aspirates will gain increasing acceptance in the management of the oligo- and azoospermic patient.     

Effects of using object self-stimulation as a reinforcer on the prevocational work rates of an autistic child

The purpose of this study was to examine the effects of object self-stimulation on the task-interrupting self-stimulatory behavior and prevocational work responses of a 13-year-old autistic boy. Using a multiple-baseline design across three diferent prevocational tasks, a systematic manipulation of object self-stimulation was associated with increases in correct rates and decreases in task-interrupting self-stimulatory behaviors. An analysis of these data indicates that self-stimulatory behavior may be shaped to facilitate performance proficiencies. Social validation information suggests that favorable generalized responding had occurred. On the basis of findings from this study, future research needs are discussed.     

Behavior, genetics and biochemistry of an allele of the mutant mouse spastic, spaAlb

A new autosomal recessive mutation, characterized by an early defect in righting reflex and stiffened gait, progression to severe spasticity, tremor and rigidity, and death before weaning, appeared spontaneously on the C57BL/6 background. It was shown to be an allele of the mutant spastic spa, and shall be known as spaAlb. Mutant levels of [3H]strychnine binding are less than 10% of control levels in the brainstem and spinal cord. Autoradiographic examination of the distribution of [3H]strychnine binding sites in the mutant confirm a greatly reduced level of binding compared to control in all areas of the spinal cord, brainstem, and midbrain.