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．     

Importance of community size in practice location decisions of final year residents

Final year residents in training in Louisiana were surveyed regarding plans for medical practice and their perceptions of the importance of various factors in choosing practice locations. Most specialty groups selected smaller communities at similar rates. Growing up in small towns is associated with wanting to practice in small towns while concerns about opportunities for the family and income of the region are associated with wanting to practice in a larger city.This study was supported by the Louisiana Council for Statewide Planning for Physician Manpower through Contract No. 23058, Louisiana Department of Health and Human Resources.Ms. Samaha is a data analyst for the Louisiana Council for Statewide Planning for Physician Manpower; Robert R. Franklin, M.D. is Executive Secretary of the Council and Assistant Professor, Department of Biostatistics and Epidemiolgy, Tulane University School of Public Health and Tropical Medicine; Janet C. Rice is Assistant Pofessor, Department of Biostatistics and Epidemiology at the Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana 70112.     

Genetic analysis of the affective disorders: summary of GAW5

Participants in the Affective Disorders component of Genetic Analysis Workshop 5 had access to five distributed data sets: 1) 187 families from the Collaborative Depression Study, 2) 202 families ascertained as part of the NIMH Family Studies on Affective Disorders, 3) a compilation of 46 pedigrees informative for X-linked markers, 4) HLA typing on 116 kindreds from the Toronto-Rochester Depression Study, and 5) 81 members of an Old Order Amish pedigree demonstrating linkage to markers on chromosome 11p. These databases are each summarized after a brief account is given of the genetics of the affective disorders and commonly used diagnoses. The emphasis of the Workshop was methodologic, with contributions divided evenly between linkage and nonlinkage applications. Contributions are summarized under four substantive areas: regressive logistic models, segregation and other familial analyses, methodologic considerations in linkage analysis, and the relationship between HLA and affective disorders.     

Actin-free Gc globulin: a rapidly assessed biomarker of organ dysfunction in acute liver failure and cirrhosis.

Reductions in serum levels of Gc globulin, a hepatically synthesized component of the extracellular actin scavenger system responsible for complexing circulating actin and attenuating intravascular microthrombus formation, are associated with poor outcome in acute liver failure. Clinically applicable assays of the important actin-free fraction (Af-Gc) have not been available until now. We measured actin-free Gc globulin levels with a novel, rapid assay in 61 cases of acute liver failure (ALF) and in 91 patients with cirrhosis (40 of whom were clinically unstable with extrahepatic organ dysfunction), and studied associations with liver dysfunction, extrahepatic organ dysfunction, indices of disseminated coagulation, and outcome. Reductions in Af-Gc levels mirrored hepatic dysfunction and organ dysfunction in both groups, and discriminated patients with poor prognosis from those with good prognosis in the ALF cohort. Levels were lowest in patients with ALF (10% of control values), but levels were also markedly reduced in both unstable (28%) and stable (44%) patients with cirrhosis. Associations with markers of disseminated intravascular coagulation were seen in both groups, most notably in the cirrhosis cohort, supporting a pathophysiological role for reduced Af-Gc in the evolution of organ dysfunction. In acetaminophen-induced ALF, Af-Gc identified patients with poor prognosis as well as did the Acute Physiology and Chronic Health Evaluation (APACHE II) score (area under the receiver operating characteristic curve, 0.7), and in cirrhosis, Af-Gc was an independent predictor of mortality by multifactorial analysis. In conclusion, the importance of Af-Gc reductions in the development of multiple organ dysfunction in ALF and cirrhosis is highlighted, probably resulting from reduced hepatic production and peripheral exhaustion of this arm of the extracellular actin scavenger system.     

Changes in the nature of sentence production during the period of grammatical development.

The sentence production capabilities of young children undergo major changes during the same period in which grammar develops. This article reports data from a cross-sectional sample of 52 children between the ages of 1;10 (years; months) and 4;0, and looks specifically at the dichotomy between stalls, sentence disruptions that are the result of glitches in sentence production, and revisions, sentence disruptions that involve self-monitoring and the rapid replacement of words or morphosyntactic alternatives. It was found that revision rate increased with level of grammatical development, but that stall rate was not related to grammatical development. These results indicate that children's capacities for self-monitoring and maintenance of multiple linguistic alternatives increase during the period of grammatical development.     

Three years of alendronate treatment results in similar levels of vertebral microdamage as after one year of treatment.

Three years of daily alendronate treatment increases microdamage in vertebral bone but does not significantly increase it beyond levels of microdamage found after 1 yr of treatment. This suggests microdamage accumulation peaks during the early period of bisphosphonate treatment and does not continue to accumulate with longer periods of treatment. INTRODUCTION: Clinically relevant doses of alendronate increase vertebral microdamage by 4- to 5-fold in skeletally mature beagles after 1 yr of treatment. The goal of this study was to determine whether microdamage would continue to accumulate with 3 yr of alendronate treatment in an intact beagle dog model. MATERIALS AND METHODS: One-year-old female beagles were treated with daily oral doses of vehicle (VEH, 1 ml/kg/d) or alendronate (ALN, 0.2 or 1.0 mg/kg/d) for 3 yr. These ALN doses were chosen to approximate, on a milligram per kilogram basis, those used to treat osteoporosis (ALN0.2) and Paget's disease (ALN1.0). Microdamage accumulation, static and dynamic histomorphometry, densitometry, and mechanical properties of lumbar vertebrae were assessed. Comparisons were made among the three groups treated for 3 yr and also within each treatment group to animals treated under the same conditions for 1 yr. RESULTS: Overall microdamage accumulation (crack surface density) was not significantly higher in animals treated for 3 yr with either dose of ALN, whereas crack density increased significantly (100%; p < 0.05) with the higher dose of ALN compared with VEH. Both ALN doses significantly suppressed the rate of bone turnover (-60% versus VEH). There was no difference among groups for any of the structural biomechanical properties-ultimate load, stiffness, or energy absorption. However, when adjusted for areal BMD, ALN-treated animals had significantly lower energy absorption (-20%) compared with VEH. Toughness, the energy absorption capacity of the bone tissue, was significantly lower than VEH for both ALN0.2 (-27%) and ALN1.0 (-33%). Compared with animals treated for 1 yr, there was no significant difference in microdamage accumulation for either ALN dose. VEH-treated animals had significantly lower bone turnover (-58%) and significantly higher levels of microdamage (+300%) compared with values in 1-yr animals. Toughness was significantly lower in animals treated for 3 yr with ALN1.0 (-18%) compared with animals treated for 1 yr, whereas there was no difference in toughness between the two treatment durations for either VEH or ALN0.2. CONCLUSIONS: Although 3 yr of ALN treatment resulted in higher microcrack density in vertebral trabecular bone compared with control dogs, the amount of microdamage was not significantly higher than animals treated for 1 yr with similar doses. This suggests that bisphosphonate-associated increases in microdamage occur early in treatment. Because toughness continued to decline significantly over 3 yr of treatment at the higher ALN dose, decreases in toughness are probably not dependent on damage accumulation.