Faculty Bibliography

BACKGROUND: We developed computer-based virtual patient (VP) cases to complement an interactive continuing medical education (CME) course that emphasizes skills practice using standardized patients (SP). Virtual patient simulations have the significant advantages of requiring fewer personnel and resources, being accessible at any time, and being highly standardized. Little is known about the educational effectiveness of these new resources. We conducted a randomized trial to assess the educational effectiveness of VPs and SPs in teaching clinical skills. OBJECTIVE: To determine the effectiveness of VP cases when compared with live SP cases in improving clinical skills and knowledge. DESIGN: Randomized trial. PARTICIPANTS: Fifty-five health care providers (registered nurses 45%, physicians 15%, other provider types 40%) who attended a CME program. INTERVENTIONS: Participants were randomized to receive either 4 live cases (n=32) or 2 live and 2 virtual cases (n=23). Other aspects of the course were identical for both groups. RESULTS: Participants in both groups were equivalent with respect to pre-post workshop improvement in comfort level (P=.66) and preparedness to respond (P=.61), to screen (P=.79), and to care (P=.055) for patients using the skills taught. There was no difference in subjective ratings of effectiveness of the VPs and SPs by participants who experienced both (P=.79). Improvement in diagnostic abilities were equivalent in groups who experienced cases either live or virtually. CONCLUSIONS: Improvements in performance and diagnostic ability were equivalent between the groups and participants rated VP and SP cases equally. Including well-designed VPs has a potentially powerful and efficient place in clinical skills training for practicing health care workers

This paper investigates the possibility of using the motion of a patient's anterior surface in combination with a motion model to compensate for internal respiratory motion during tracked biopsies. Position data from two electromagnetically tracked sensors, one placed on the patient's sternum, the other incorporated into a biopsy needle, were acquired during a liver biopsy. The data were used to evaluate the correlation between the position measurements of the two sensors and to derive an affine motion model to assess respiratory motion compensation for image-guided interventional procedures. The correlation reached up to 94% for ranges of steady respiration. The residual motion of the internal sensor after compensation is reduced by a factor of approximately four.

Immune and bone cells are functionally coupled by pro-inflammatory cytokine intercellular signaling networks common to both tissues and their crosstalk may contribute to the etiologies of some immune-associated bone pathologies. For example, the receptor activator of NF-kappaB ligand (RANKL)/osteoprotegerin (OPG)/receptor activator of NF-kappaB (RANK) signaling axis plays a critical role in dendritic cell (DC) function as well as bone remodeling. The expression of RANKL by immune cells may contribute to bone loss in periodontitis, arthritis, and multiple myeloma. A recent discovery reveals that DCs release the chromatin protein high mobility group box 1 (HMGB1) as a potent immunomodulatory cytokine mediating the interaction between DCs and T-cells, via HMGB1 binding to the membrane receptor for advanced glycation end products (RAGE). To determine whether osteoblasts or osteoclasts express and/or release HMGB1 into the bone microenvironment, we analyzed tissue, cells, and culture media for the presence of this molecule. Our immunohistochemical and immunocytochemical analyses demonstrate HMGB1 expression in primary osteoblasts and osteoclasts and that both cells express RAGE. HMGB1 is recoverable in the media of primary osteoblast cultures and cultures of isolated osteoclast precursors and osteoclasts. Parathyroid hormone (PTH), a regulator of bone remodeling, attenuates HMGB1 release in cultures of primary osteoblasts and MC3T3-E1 osteoblast-like cells but augments this release in the rat osteosarcoma cell line UMR 106-01, both responses primarily via activation of adenylyl cyclase. PTH-induced HMGB1 discharge by UMR cells exhibits similar release kinetics as reported for activated macrophages. These data confirm the presence of the HMGB1/RAGE signaling axis in bone.

OBJECTIVES: A method for the induction of complete heart block (CHB) by ethanol injection and its success rate in a pig model of acute right ventricular failure is reported. Additionally, a review of the literature for the induction of CHB in laboratory animals is detailed. The literature review was undertaken to both compare our rate of success with other methods and provide insight into our technique and refine its implementation. BACKGROUND: Animal models of CHB have facilitated the understanding of therapeutics for various cardiac pathologies in humans. In our laboratory, CHB in pigs is used for complete control of heart rhythm in studies of biventricular pacing. MATERIALS AND METHODS: Experiments carried out on pigs in our laboratory that required the induction of CHB were reviewed retrospectively. In addition, review of the literature for creating CHB in animals was undertaken. Our success rate was compared to that of other groups. RESULTS: Our success rate (93%) is similar to other models of CHB, in general, and to those models that used the injection of caustic substances with thoracotomy. CONCLUSIONS: Review of the literature indicates that our success rate is comparable to other groups and that, although many approaches have been described in both open- and closed-chest models, success is likely dependent on the practice and skill of the experimenter. In addition, review of the literature has afforded us new perspectives on the experimental induction of CHB.

The media have begun beating the stuffing out of another drug, Ambien, as they show pictures of drowsy sleepwalkers cooking or stuffing themselves at the refrigerator in the middle of the night, or write stories about the risks to motor vehicle operators. The fact is, the vast majority of the author's patients experience no side effects whatsoever. In fact, Ambien is so well tolerated and effective that it has changed the way doctors treat insomnia. Medical misinformation of this kind helps neither doctors nor their patients

TALKING WITH DOCTORS By David Newman. 199 pp. Hillsdale, NJ., Analytic Press, 2006. $32.50. ISBN 0-88163-446-8

In 2001, New York City implemented genotyping to its tuberculosis (TB) control activities by using IS6110 restriction fragment length polymorphism (RFLP) and spoligotyping to type isolates from culture-positive TB patients. Results are used to identify previously unknown links among genotypically clustered patients, unidentified sites of transmission, and potential false-positive cultures. From 2001 to 2003, spoligotype and IS6110-based RFLP results were obtained for 90.7% of eligible and 93.7% of submitted isolates. Fifty-nine (2.4%) of 2,437 patient isolates had false-positive culture results, and 205 genotype clusters were identified, with 2-81 cases per cluster. Cluster investigations yielded 57 additional links and 17 additional sites of transmission. Four additional TB cases were identified as a result of case finding initiated through cluster investigations. Length of unnecessary treatment decreased among patients with false-positive cultures

As the population increases, older people have the opportunity to travel for longer periods and to destinations that are quite different from what they are used to. Older people do indeed have more ongoing medical issues and some limitations due to the aging process. Most of the time these chronic conditions are not a contraindication to travel. Preparing for travel frequently involves starting an exercise program, updating routine immunizations such as tetanus, pneumonia, and influenza as well as getting destination specific immunizations such as hepatitis, yellow fever and typhoid. Medications should be reviewed as they relate to altitude, climate and concurrent travel medications including malaria prophylaxis. There are many organizations and foundations that deal with travel and specific medical problems such as diabetes, asthma, dialysis and for those with spinal cord injuries. The traveler would be wise to seek the advice of specialists related to their specific medical condition as well as a travel medical physician. One should also be sure that their medical insurance would cover them in a foreign country

Counselling pregnant women seeking advice about travel should begin with a frank, in-depth discussion about their contemplated trip. While most travel during pregnancy is relatively safe, some women should be urged not to go on their planned trip, or to change their itineraries. But some women are not receptive to such advice. Much of today's popular culture preaches that pregnancy is a normal phase of life, not a health issue, and that restrictions placed on women during pregnancy by the medical profession are largely unnecessary. The women must truly and totally understand potential risks and realise that medical science does not have all the answers, especially as far as risks to the foetus are concerned. The women should be aware that travel may remove them from access to medical care, require immunisations and prophylactic medications, involve long hours sitting in aircraft, necessitate dietary restrictions at the destination, and expose them to extremes of climate, to mention just a few