Recent Publications by CFE Educators

PURPOSE

Block ambulatory rotations and longitudinal ambulatory care experiences are now common in U.S. medical schools, but little is known about their efficacy. Through a structured review of the medical literature from 1966 through March 2000, the authors summarize the characteristics of, the evidence for, and the evaluation of longitudinal ambulatory care rotations.

METHOD

The authors searched Medline using the terms "outpatients," "continuity of patient care," "ambulatory care," "mentors," "preceptorship," "graduate medical education," "curriculum," and "clinical clerkship" cross-matched to "medical students" and "internship and residency" for literature published from 1966 through March 2000. They narrowed the list to only articles containing empirical outcome data focusing on medical students' experiences in longitudinal ambulatory care rotations. Each study was scored to assess its strengths and weaknesses.

RESULTS

Seven articles met the search criteria. The articles identified the benefits of longitudinal ambulatory care experiences, including developing effective patient interactions and understanding chronic diseases. There were little or no differences in the students' overall knowledge acquisition when those with longitudinal experiences were compared with those in block rotations.

DISCUSSION

Although longitudinal ambulatory care experiences are now common in medical schools, evidence supporting their widespread implementation is sparse. Few studies employ rigorous methods to evaluate educational outcomes. Research to identify benefits and costs, improve the quality and consistency of the students' experiences, and develop other innovative ways of teaching and learning ambulatory care is needed.

PURPOSE

Time-pressured interactions with little direct observation or feedback characterize teaching in ambulatory settings. The authors report findings from the literature on teaching and learning in the ambulatory setting and propose opportunities for further research that addresses these barriers.

METHOD

The authors searched 1995-1999 databases for all empirical studies that focused on research conducted in ambulatory settings. Publications were reviewed for evidence of inclusion criteria. Findings were sorted into categories previously described for defining and evaluating quality of ambulatory care educational programs.

RESULTS

Most studies were conducted in departments of internal medicine (40%), focused on medical students (43%), and took place in a single program (77%), making generalizations difficult. Students and residents are learning in ambulatory environments, and the types of patients they encounter are likely to prepare them for practice. Patient care outcomes have emerged as a measure of learning. Teachers may be the single most important factor, yet they lack self-confidence as teachers. Community-based preceptors teach because of enjoyment of teaching and the opportunity to stay current. However, none of the studies addressed the impact of the Medicare documentation requirements on satisfaction with teaching. Teaching settings cost about one third more than non-teaching settings to operate.

CONCLUSION

This review identifies many gaps in our knowledge of effective clinical teaching practices, and of learning environments in which that teaching takes place. The predominance of single-institution studies limits generalizability of current findings. A prioritized research agenda should be established and funded, focusing on improving the efficiency and effectiveness of teaching and learning in ambulatory settings.

Human alveolar macrophages have both lipopolysaccharide (LPS)-induced and constitutive phosphatidylinositol 3-kinase (PI3K) activity. We observed that blocking PI3K activity increased release of prostaglandin E2 after LPS exposure, and increasing PI3K activity (interleukin-13) decreased release of prostaglandin E2 after LPS exposure. This was not because of an effect of PI3K on phospholipase 2 activity. PI3K inhibition resulted in an increase in cyclooxygenase 2 (COX2) protein, mRNA, and mRNA stability. PI3K negatively regulated activation of the p38 pathway (p38, MKK3/6, and MAPKAP2), and an active p38 was necessary for COX2 production. The data suggest that PI3K inhibition of p38 modulates COX2 expression via destabilization of LPS-induced COX2 mRNA.

The peripheral branch of primary sensory neurons regenerates after injury, but there is no regeneration when their central branch is severed by spinal cord injury. Here we show that microinjection of a membrane-permeable analog of cAMP in lumbar dorsal root ganglia markedly increases the regeneration of injured central sensory branches. The injured axons regrow into the spinal cord lesion, often traversing the injury site. This result mimics the effect of a conditioning peripheral nerve lesion. We also demonstrate that sensory neurons exposed to cAMP in vivo, when subsequently cultured in vitro, show enhanced growth of neurites and an ability to overcome inhibition by CNS myelin. Thus, stimulating cAMP signaling increases the intrinsic growth capacity of injured sensory axons. This approach may be useful in promoting regeneration after spinal cord injury.

The Dachshund proteins are essential components of a regulatory network controlling cell fate determination. They have been implicated in eye, limb, brain, and muscle development. These proteins cannot be assigned to any recognizable structural or functional class based on amino acid sequence analysis. The 1.65 A crystal structure of the most conserved domain of human DACHSHUND is reported here. The protein forms an alpha/beta structure containing a DNA binding motif similar to that found in the winged helix/forkhead subgroup of the helix-turn-helix family. This unexpected finding alters the previously proposed molecular models for the role of Dachshund in the eye determination pathway. Furthermore, it provides a rational framework for future mechanistic analyses of the Dachshund proteins in several developmental contexts.

Sexual reproduction and recombination are essential for the survival of most eukaryotic populations. Until recently, the impact of these processes on the structure of bacterial populations has been largely overlooked. The advent of large-scale whole-genome sequencing and the concomitant development of molecular tools, such as microarray technology, facilitate the sensitive detection of recombination events in bacteria. These techniques are revealing that bacterial populations are comprised of isolates that show a surprisingly wide spectrum of genetic diversity at the DNA level. Our new awareness of this genetic diversity is increasing our understanding of population structures and of how these affect host pathogen relationships.