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Although sentinel lymph node (SLN) biopsy is rapidly becoming the standard of care for small breast cancers the optimal radiocolloid injection technique remains controversial. We report our experience with sequential dermal-peritumoral radiocolloid injection that takes advantage of both techniques. One hundred eighteen patients with clinical stage Ti8, T1, T2 and N0 breast cancer underwent SLN biopsy at the University of Florida. Twelve to 18 hours before surgery patients received either an injection of 0.5 to 1.0 mCi 50:50 filtered:unfiltered technetium sulfur colloid into the dermis overlying the tumor and/or a peritumoral injection of a 3 to 4-mCi of radiocolloid 30 minutes later. Dynamic lymphoscintigraphy was performed and the topographical location of all imaged lymph nodes was marked on the skin. The next morning the surgeon utilized a hand-held gamma probe to remove all SLN(s) defined as any lymph node with radioactive counts 10 per cent or more of the ex vivo counts of the most radioactive SLN [internal mammary (IM) nodes were not removed]. The SLN identification rate was 98.5 per cent (3 IM nodes) for dermal injection (D), 83.3 per cent (1 IM node) for peritumoral injection (P), and 100 per cent (14 IM nodes) for sequential dermal-peritumoral injection (DP) ( p < 0.05 DP versus D). Sequential DP 50:50 filtered:unfiltered technetium sulfur colloid injection results in a rapid, high SLN identification rate that persists until surgery the next morning. Delineation of nonaxillary SLNs may lead to more accurate breast cancer staging and may also influence the delivery of IM node radiation.

Background Endotoxin (lipopolysaccharide) stimulates transmembrane l -arginine transport in pulmonary artery endothelial cells (PAECs). The proinflammatory cytokines tumor necrosis factor (TNF) and interleukin-1 (IL-1) mediate many of the pathophysiologic effects of endotoxemia and sepsis. Endothelial cells secrete TNF and IL-1 in response to endotoxin. We hypothesize that lipopolysaccharide stimulation of plasma membrane l -arginine transport is mediated via an autocrine cytokine loop involving TNF and IL-1. Methods. Confluent porcine PAECs were incubated with various concentrations of lipopolysaccharide, TNF, or IL-1, and arginine uptake was determined by assaying the uptake of 3 H- l -arginine in the presence or absence of Na + at different time points. PAECs were then incubated with lipopolysaccharide or saline solution after pretreatment with either anti-TNF antibody or IL-1-receptor antagonist, and transport was measured 12 hours later. Results. Lipopolysaccharide, IL-1, and TNF all increased both Na + -dependent and Na + -independent carrier-mediated l -arginine transport in a fashion that was both time and dose dependent. Maximal increases in stimulated arginine uptake occurred 8 hours after exposure to the cytokines and 12 hours after exposure to lipopolysaccharide. Pretreatment of endothelial cells with anti-TNF antibody blocked lipopolysaccharide stimulation of both Na + -independent and Na + -dependent transport by 100% and 90%, respectively. In addition, IL-1-receptor antagonist inhibited lipopolysaccharide stimulation of both Na + -independent and Na + -dependent transport by 65% and 85%, respectively. Conclusions. The marked increase in carrier-mediated l -arginine transport activity produced by lipopolysaccharide, IL-1, and TNF may represent an adaptive response by the pulmonary endothelium to support arginine-dependent biosynthetic pathways during sepsis. Furthermore, lipopolysaccharide stimulation of arginine transport is mediated in part through an autocrine mechanism involving IL-1 and TNF.

We introduce the notion of Shader Lamps Virtual Patients (SLVP) - the combination of projector-based Shader Lamps Avatars and interactive virtual humans. This paradigm uses Shader Lamps Avatars technology to give a 3D physical presence to conversational virtual humans, improving their social interactivity and enabling them to share the physical space with the user. The paradigm scales naturally to multiple viewers, allowing for scenarios where an instructor and multiple students are involved in the training. We have developed a physical-virtual patient for medical students to conduct ophthalmic exams, in an interactive training experience. In this experience, the trainee practices multiple skills simultaneously, including using a surrogate optical instrument in front of a physical head, conversing with the patient about his fears, observing realistic head motion, and practicing patient safety. Here we present a prototype system and results from a preliminary formative evaluation of the system.

The Autosuture™ Endostitch ™ device (Covidien, CT) is difficult to learn. In particular, the handle requires the use of a toggle which is unique in this instrument. We have developed a virtual reality trainer for the device that offers the use of the actual instrument handle while creating a visible virtual instrument tip complete with virtual needle and suture on a monitor. This report represents the development and initial validation experiments for the device.

We describe a fully interactive, low-overhead and robust peritoneum representation allowing for probing and cutting. The peritoneum implementation has been tested within a surgical illustration environment.

Background: Gastroparesis following lung transplantation can complicate medical management leading to malnutrition, weight loss, and erratic absorption of immunosuppressive medications, which are all important factors in the success of grafts. Gastric electrical stimulation has been shown to reduce the frequency of nausea and vomiting and lead to weight gain in patients with gastroparesis refractory to standard medical treatment; however, it has not yet been reported as being used for the treatment of gastroparesis in lung transplant recipients. Methods: We report the case of a female bilateral lung transplant recipient suffering from severe gastric reflux and severe gastroparesis, who was successfully treated with simultaneous creation of a laparoscopic Nissen fundoplication and placement of a gastric stimulator. Results: The patient noted an immediate and sustained decrease in her symptoms of nausea and vomiting, and an increased appetite, and less variability in the serum levels of her immunosuppressive medication. Conclusion: Lung transplant recipients with severe gastroparesis and reflux may benefit from Nissen fundoplication and gastric electrical stimulation.

Modeling soft tissue for surgery simulation is a challenging task due to the complex way that the tissue can deform and interact with virtual surgical tools manipulated by user. One soft tissue that is ubiquitous but often not modeled, is fatty tissue. Here we present a novel fatty tissue model based on the mass-spring system on the Graphics Processing Unit (GPU) as part of our Toolkit for Illustration of Procedures in Surgery (TIPS). The user can interact with the fatty tissue in real time via a handheld haptic stylus that represents a virtual surgical tool in TIPS environment. The currently available interactions are palpation, grasp, and cut.

Good surgical training depends greatly on case experiences that have been difficult to model in software since current training technology does not provide the flexibility to teach and practice uncommon procedures, or to adjust a training scenario on the fly. The TIPS kit aims to overcome these limitations. To the expert, it presents visual and haptic tools that make illustrating procedures easy and can model unusual anatomic variations. For a non-specialist, it provides a locally customized learning environment and repeated practice in a safe environment. We used the toolkit to illustrate removal of the adrenal gland.

Real-time, plausible visual and haptic feedback of deformable objects without shape artifacts is important in surgical simulation environments to avoid distracting the user. We propose to leverage highly parallel stream processing, available on the newest generation graphics cards, to increase the level of both visual and haptic fidelity. We implemented this as part of the University of Florida's haptic surgical authoring kit.

Recently, there has been a decrease in the number of graduating U.S. medical students entering surgical residency. Therefore the purpose of this study was to examine student career choice over the last two decades (1982-2002) at the University of Florida. Residency match and academic performance data for the University of Florida medical school graduates from 1982 through 2002 were obtained from the College of Medicine's Offices of Student Affairs and Education. The percentage of medical students pursuing a career in surgery rose slightly in the 1980s to peak at 22 per cent of the graduating class in 1991 and then steadily declined in the 1990s to 15 per cent in the graduating class of 2002. The percentage of women entering surgical residency has remained relatively constant (20-year mean = 6.41 +/- 0.77) despite a significant increase percentage of women in the graduating class (Class of 1983, 24%; Class of 2002, 55%). The percentage of graduating students entering a primary care residency has remained relatively constant (54.4 +/- 1.24), whereas the number of students pursuing a "lifestyle-friendly" specialty has increased substantially over the last two decades (Class of 1983, 9%; Class of 2002, 22%). In addition the mean overall grade point average of female students entering 'lifestyle-friendly' specialty residencies is significantly higher than the mean overall grade point average of all students entering a surgical residency (3.61 +/- 0.38 versus 3.48 +/- 0.35; P0.05). Similar to national trends the percentage of senior medical students entering surgical residency at the University of Florida is gradually declining. Although the percentage of graduating medical students entering primary care has remained relatively constant the number of students following a lifestyle-friendly specialty has steadily increased. A disproportionately low number of graduating female medical students are entering surgical residency. By one measure of academic performance the quality of female graduates entering lifestyle-friendly specialty residencies is superior to that of students entering surgical residency. Lifestyle issues are increasingly important in student career choice decisions.

The technique of identifying the sentinel lymph node (SLN) varies from each individual institution. Generally, the highest isotope count in a lymph node is considered the SLN, whereas other radioactive nodes might also be removed. The purpose of our study was to determine if the hottest node was always the tumor-containing node. Two hundred forty-seven breast cancer patients underwent SLN biopsy from April 1998 to April 2002. Lymphatic mapping involved a radiocolloid injection and lymphoscintigraphy followed by intraoperative assessment with a hand-held gamma probe. All SLN(s) with radioactive counts 10 per cent or more of the ex vivo counts of the most radioactive SLN were removed. The SLN were sliced at 2-mm intervals with 4–μm step-sections (92–μm spacing) and evaluated by microscopy and immunohistochemistry. One hundred twenty (49%) of the 247 patients had 2 or more nodes resected. Of these 120 patients, 33 (28%) had a tumor-bearing node. In 25 (74%) cases, the tumor-bearing node was the most radioactive; however, in 8 (26%) cases, the positive node was a lesser reactive node. Although the most radioactive node in a draining basin is considered the SLN, this is often not the metastatic node. Therefore, all nodes with significant radioactive counts must be removed to ensure accurate staging.