Use of a continuing medical education course to improve fellows' knowledge and skills in esophageal disorders.

Advanced esophageal endoscopic procedures such as stricture dilation, hemostasis tools, and stent placement as well as high-resolution manometry (HRM) interpretation are necessary skills for gastroenterology fellows to obtain during their training. Becoming proficient in these skills may be challenging in light of higher complication rates compared with diagnostic procedures and infrequent opportunities to practice these skills. Our aim was to determine if intensive training during a continuing medical education (CME) course boosts the knowledge and skills of gastroenterology fellows in esophageal diagnostic test interpretation and performance of therapeutic procedures. This was a pretest-posttest design without a control group of a simulation-based, educational intervention in esophageal stricture balloon dilation and HRM interpretation. The participants were 24 gastroenterology fellows from 21 accredited US training programs. This was an intensive CME course held in Las Vegas, Nevada from August 7 to August 9, 2009. The research procedure had two phases. First, the subjects were measured at baseline (pretest) for their knowledge and procedural skill. Second, the fellows received 6 hours of education sessions featuring didactic content, instruction in HRM indications and interpretation, and deliberate practice using an esophageal stricture dilation model. After the intervention, all of the fellows were retested (posttest). A 17-item checklist was developed for the esophageal balloon dilation procedure using relevant sources, expert opinion, and rigorous step-by-step procedures. Nineteen representative HRM swallow studies were obtained from Northwestern's motility lab and formed the pretest and posttest in HRM interpretation. Mean scores on the dilation checklist improved 81% from 39.4% (standard deviation [SD]= 33.4%) at pretest to 71.3% (SD = 29.5%) after simulation training (P < 0.001). HRM mean examination scores increased from 27.2% (SD = 16.4%) to 46.5% (SD = 15.8%), representing a 71% improvement (P < 0.001). Pearson's correlations indicated there was no correlation between pretest performance, medical knowledge measured by United States Medical Licensing Examination examinations, prior clinical experience, or procedural self-confidence and posttest performance of esophageal dilation or HRM interpretation. The education program was rated highly. This study demonstrated that a CME course significantly enhanced the technical skills and knowledge of gastroenterology fellows in esophageal balloon dilation and HRM interpretation. CME courses such as this may be a valuable adjunct to standard fellowship training in gastroenterology.

Patterns of nurse-physician communication and agreement on the plan of care.

BACKGROUND: Interdisciplinary communication is critically important to provide safe and effective care, yet it has been inadequately studied for hospitalised medical patients. Our objective was to characterise nurse-physician communication and their agreement on patients' plan of care. METHODS: During a one-month period, randomly selected hospitalised patients, their nurses and their physicians were interviewed. Nurses and physicians were asked to identify one another, whether communication had occurred, and about six aspects of the plan of care. Two internists rated nurse-physician agreement on aspects of the plan of care as none, partial or complete agreement. Measures included the percentage of nurses and physicians able to identify one another and reporting communication and the percentage of nurse-physician pairs in agreement on aspects of the plan of care. RESULTS: 310 (91%) and 301 (88%) of 342 eligible nurses and physicians completed interviews. Nurses correctly identified patients' physicians 71% of the time and reported communicating with them 50% of the time. Physicians correctly identified the patients' nurses 36% of the time and reported communicating with them 62% of the time. Physicians and nurses showed no agreement on aspects of the plan of care ranging from 11% for planned procedures to 42% for medication changes. CONCLUSIONS: Nurses and physicians did not reliably communicate with one another and were often not in agreement on the plan of care for hospitalised medical patients.

Tooth and periodontal disease: a review for the primary-care physician.

Dental diseases are widespread and are often underrecognized and treated. Caries and periodontal disease are common dental conditions that cause the majority of tooth loss. Although these conditions are preventable, many persons do not receive regular dental care and have acute problems when seen by their physician. Dental diseases frequently affect patients with multiple systemic disorders, including autoimmune disorders, diabetes, and human immunodeficiency virus (HIV) infection. The presence of dental disease may trigger inflammatory responses and have systemic consequences. Since dental disease affects almost all individuals, physicians should be able to recognize common conditions such as caries, periodontal disease, pulpitis, and dental abscess. In addition to initiating treatment and appropriate dental referrals, physicians should be familiar with the management of antibiotics and medications in the perioperative period. Another important role for physicians is to help reduce the societal and economic impact of these diseases through patient education and prevention.

EMA: a developmentally regulated cell-surface glycoprotein of CNS neurons that is concentrated at the leading edge of growth cones.

To identify cell-surface molecules that mediate interactions between neurons and their environment during neural development, we used monoclonal antibody techniques to define a developmentally regulated antigen in the central nervous system of the mouse. The antibody we produced (2A1) immunolabels cells throughout the central nervous system; we analyzed its distribution in the developing cerebral cortex, where it is expressed on cells very soon after they complete mitosis and leave the periventricular proliferative zone. Expression continues into adult life. The antibody also labels the epithelium of the choroid plexus and the renal proximal tubules, but does not label neurons of the peripheral nervous system in the dorsal root ganglia. In dissociated cell culture of embryonic cerebral cortex, 2A1 labels the surface of neurons but not glia. Immunolabeling of neurons in tissue culture is particularly prominent on the edge of growth cones, including filopodia and the leading edge of lamellipodia, when observed with either immunofluorescence or freeze-etch immunoelectron microscopy. Immunopurification with 2A1 of a CHAPS-extracted membrane preparation from brains of neonatal mice produces a broad (32-36 kD) electrophoretic band and a less prominent 70 kD band that are sensitive to N-glycosidase but not endoglycosidase H. Thus the 2A1 antibody recognizes a developmentally regulated, neuronal cell surface glycoprotein (or glycoproteins) with complex N-linked oligosaccharide side chains. We have termed the glycoprotein antigen EMA because of its prominence on the edge membrane of growth cones. EMA is similar to the M6 antigen (Lagenaur et al: J. Neurobiol. 23:71-88, 1992) in apparent molecular weight, distribution in tissue sections, and immunoreactivity on Western blots, suggesting that the two antigens are similar or identical. Expression of EMA is a very early manifestation of neuronal differentiation; its distribution on growth cones suggests a role in mediating the interactions between growth cones and the external cues that guide them.

Extension of filopodia by motor-dependent actin assembly.

A variety of mechanisms have been proposed to explain the forward extension of cytoplasm in advancing cells and axonal growth cones, including actin polymerization and osmotic swelling. Based on our observations of the filopodia of cultured neuronal growth cones, we propose a mechanism involving motor-induced extension and retraction. We observed that filopodia (actin-based protrusions 0.2-0.5 mu in diameter) extend and retract from growth cone lamellae at the same rate. Further, force is generated at the tips of filopodia which is sufficient to produce compressive buckling of the proximal portion of the filopodium. From our analysis of these movements we suggest that a motor protein powers both the extension and retraction of filopodia.

Concentration of membrane antigens by forward transport and trapping in neuronal growth cones.

Formation of the nervous system requires that neuronal growth cones follow specific paths and then stop at recognition signals, sensed at the growth cone's leading edge. We used antibody-coated gold particles viewed by video-enhanced differential interference contrast microscopy to observe the distribution and movement of two cell surface molecules, N-CAM and the 2A1 antigen, on growth cones of cultured cortical neurons. Gold particles are occasionally transported forward at 1-2 microns/s to the leading edge where they are trapped but continue to move. Concentration at the edge persists after cytochalasin D treatment or ATP depletion, but active movements to and along edges cease. We also observed a novel outward movement of small cytoplasmic aggregates at 1.8 microns/s in filopodia. We suggest that active forward transport and trapping involve reversible attachment of antigens to and transport along cytoskeletal elements localized to edges of growth cones.

The ontogeny of specific retrograde transport of nerve growth factor by motoneurons of the brainstem and spinal cord.

Radiolabeled Nerve Growth Factor (NGF) was injected into either the mandibular process of the first visceral arch or the limb bud of chick embryos at Days 3.5-14 or Days 4-13 of incubation, respectively. Control embryos received injections of labeled cytochrome-C or labeled NGF plus an excess of unlabeled NGF. The tissues were then processed for autoradiography. The 125I-NGF was retrogradely transported by motoneurons of the trigeminal (V) motor nucleus on Days 3.5-8 of incubation, but not at later stages. Similar transport was seen in motoneurons of the spinal cord lateral motor column from Days 4-10 of incubation, but not at later stages. Sensory neurons of the V ganglion and of the dorsal root ganglia transported NGF at all injection ages. In no instance was the 125I-cytochrome-C transported by sensory or motor neurons. The injection of an excess of cold NGF along with labeled NGF resulted in no evidence of retrograde transport of the labeled NGF indicating that the transport was saturable. The time of transport by these brainstem and spinal cord motoneurons corresponds closely to the points during development at which they have been found to exhibit specific NGF binding. The present results, then, provide further evidence for a possible biological role for NGF during early developmental stages of these motoneuron populations.

The response of cultured trigeminal and spinal cord motoneurons to nerve growth factor.

Dissociated neurons from the trigeminal (V) region of the metencephalic basal plate or the ventral spinal cord from chick embryos of Day 4 (V basal plate) or Day 5 (spinal cord) were cultured on a laminin substratum either in the presence of nerve growth factor (NGF) or in control medium. Assessment was made of neuronal survival, the amount of neurite elaborated, and the percentage of neurons initiating neurites. The presence of motoneurons was verified by retrograde labeling with the fluorescent dye diI. NGF was found to significantly increase the quantity of neuritic processes produced by the spinal cord dissociates at both 24 and 48 hr in vitro. The percentage of neurons initiating neuritic processes was significantly increased by NGF in the trigeminal population at 48 hr in vitro. Neuronal survival was not enhanced by NGF in either group. Both trigeminal and spinal cord neurons were also found to specifically bind 125I-NGF in culture. These results provide direct evidence for an influence of NGF on process formation of early embryonic motoneurons in culture.

Retrograde transport of NGF by early chick embryo spinal cord motoneurons.

Neuronal retrograde transport of nerve growth factor (NGF) was examined in chick embryos at 5, 6, and 7 days of incubation. Radiolabeled NGF was injected in the target limb muscle and the retrograde transport was viewed following processing for autoradiography. Silver grains were localized in the peripheral nerve, in the ventral root, in neuronal cell bodies within the dorsal root ganglion, and in motoneurons of the lateral motor column. Comparable injections of 125I-cytochrome c resulted in the presence of label at the peripheral injection site only. The possible developmental significance of these observations is discussed.

Specific responsiveness of chick trigeminal motor nucleus explants to target-conditioned media.

Explants of the neural tube from stage 11 chick embryos containing the metencephalic trigeminal (V) motor nucleus were cultured in standard control medium, in medium conditioned by appropriate target musculature (the mandibular process of the first visceral arch that gives rise to jaw musculature innervated by motor V) or in medium conditioned by inappropriate target musculature (rostral limb bud tissue). The appropriate and inappropriate muscle tissues were of the same developmental stage (stage 22) and were in similar states of differentiation. At this point in vivo, both are just beginning to be innervated. The neuritic outgrowth from the explants was quantified after 6 days in vitro. While explants from all three groups appeared healthy and exhibited some neuritic outgrowth, the density and complexity of this growth was significantly greater in the group cultured with the appropriate (jaw) muscle-conditioned medium. Growth in this group significantly surpassed that of both the control and the inappropriate muscle-conditioned medium group did not differ from the control group. These results demonstrate a specific responsiveness of the trigeminal motor nucleus population to its appropriate target tissue. Since relatively small amounts of the muscle-conditioned medium were used with each explant, it is suggested that there is a high degree of sensitivity of this population to factors present in their target at the time innervation would normally be occurring. It is hypothesized that such selective responsiveness may play a role in guiding or sustaining growth during normal neurogenesis.

Patterns of extraocular innervation by the oculomotor complex in the chick.

The horseradish peroxidase retrograde tracer technique was used to map the projection pattern of the oculomotor nuclear complex to the extraocular muscles in the chick embryo. The following projection pattern was found: The dorsolateral oculomotor subnucleus innervates the ipsilateral inferior rectus muscle, the dorsomedial subnucleus innervates the ipsilateral medial rectus muscle, a lateral division of the ventromedial subnucleus innervates the ipsilateral inferior oblique muscle, and a medial division of the ventromedial subnucleus innervates the contralateral superior rectus muscle. The so-called central nucleus also innervates the contralateral superior rectus muscle. This pattern was extremely discrete, with virtually no overlapping representations. These results provide the first evidence for a functional medial-lateral subdivision of the ventromedial subnucleus. This pattern relates to the unusual development of this subnucleus and suggests that only part of the primordium for this cell group migrates across the midline during its ontogeny, rather than all of it, as was previously believed. The subnuclear organization of the avian oculomotor complex is also considered in comparison to such functional organization in other species.