Computer-aided surgical planning in the treatment of soft-tissue sarcoma

INTRODUCTION

Soft-tissue sarcoma resections are often highly complex procedures that demand meticulous pre-operative planning in order to maximise the potential for complete excision with clear margins, while preserving vital neurovascular structures and muscle groups.

SUBJECTS AND METHODS

We present a computer-aided model for surgical planning using Microsoft Powerpoint as a tool for cross referencing magnetic resonance images and normal anatomical diagrams.

RESULTS

Using this system the operator follows a sequence of pre-planned steps, minimising intra-operative decision making and unexpected adverse events. Four case studies are discussed.

CONCLUSIONS

The visual plan optimises the potential to meet surgical and oncological goals, and serves as an excellent nct to the operation note for documentation of the procedure.     

Utilization of standardized patients to evaluate clinical and interpersonal skills of surgical residents

BACKGROUND: This project was designed to determine the growth of interpersonal skills during the first year of a surgical residency. METHODS: All categorical surgical residents were given a clinical skills examination of abdominal pain using standardized patients during their orientation (T1). The categorical residents were retested after 11 months (T2). The assessment tool was based on a 12-item modified version of the 5-point Likert Interpersonal Scale (IP) used on the National Board of Medical Examiners prototype Clinical Skills Examination and a 24-item, done-or-not-done, history-taking checklist. Residents' self-evaluation scores were compared to standardized patients' assessment scores. Data were analyzed using the Pearson correlation coefficient, Wilcoxon signed rank test, Student t test, and Cronbach alpha. RESULTS: Thirty-eight categorical residents were evaluated at T1 and T2. At T1, in the history-taking exercise, the scores of the standardized patients and residents correlated (Pearson = .541, P = .000). In the interpersonal skills exercise, the scores of the standardized patients and residents did not correlate (Pearson = -0.238, P = .150). At T2, there was a significant improvement in the residents' self-evaluation scores in both the history-taking exercise (t = -3.280, P = .002) and the interpersonal skills exercise (t = 2.506, P = 0.017). In the history-taking exercise, the standardized patients' assessment scores correlated with the residents' self-evaluation scores (Pearson = 0.561, P = .000). In the interpersonal skills exercise, the standardized patients' assessment scores did not correlate with the residents' self-evaluation scores (Pearson = 0.078, P = .646). CONCLUSIONS: Surgical residents demonstrate a consistently low level of self-awareness regarding their interpersonal skills. Observed improvement in resident self-evaluation may be a function of growth in self-confidence.     

Evaluating the contribution of soil properties to modifying lead phytoavailability and phytotoxicity

Soil properties affect Pb bioavailability to human and ecological receptors and should be considered during ecological risk assessment of contaminated soil. We used path analysis (PA) to determine the relative contribution of soil properties (pH, organic C [OC], amorphous Fe and Al oxides [FEAL], and cation-exchange capacity [CEC]) in modifying Pb bioavailability. The response of biological endpoints (bioaccumulation and dry matter growth [DMG]) of lettuce (Lactuca sativa) grown on 21 Pb-spiked (2,000 mg/kg) soils were determined. Lettuce tissue Pb ranged from 3.22 to 233 mg/kg, and relative DMG ranged from 2.5 to 88.5% of their respective controls. Simple correlation showed strong relationships between CEC and OC (p < 0.01) and weaker relationships between pH and FEAL (p < 0.05) and Pb bioaccumulation. Results of PA suggest that soil pH increased the negative surface charge of organic matter and clay, thereby increasing CEC and decreasing Pb bioaccumulation. Also, the direct effect of OC on tissue Pb can be attributed to formation of surface Pb complexes by organic matter functional group ligands. Increased OC and/or CEC reduced Pb solubility and bioavailability in the 21 soils in the present study. The relative importance of soil properties likely will vary between studies employing different soils. Soil properties should be considered during the ecological risk assessment of metal in contaminated soils. Path analysis is useful for ecological studies involving soils with a wide range of physicochemical properties and can assist in site risk assessment of metals and remediation decisions on contaminated sites.     

Optimization of chromone-2-carboxamide melanin concentrating hormone receptor 1 antagonists: assessment of potency, efficacy, and cardiovascular safety

Evaluation of multiple structurally distinct series of melanin concentrating hormone receptor 1 antagonists in an anesthetized rat cardiovascualar assay led to the identification of a chromone-2-carboxamide series as having excellent safety against the chosen cardiovascular endpoints at high drug concentrations in the plasma and brain. Optimization of this series led to considerable improvements in affinity, functional potency, and pharmacokinetic profile. This led to the identification of a 7-fluorochromone-2-carboxamide (22) that was orally efficacious in a diet-induced obese mouse model, retained a favorable cardiovascular profile in rat, and demonstrated dramatic improvement in effects on mean arterial pressure in our dog cardiovascular model compared to other series reported by our group. However, this analogue also led to prolongation of the QT interval in the dog that was linked to affinity for hERG channel and unexpectedly potent functional blockade of this ion channel.     

Redo ileal pouch-anal anastomosis for malfunctioning pouches-acceptable alternative to permanent ileostomy?

BACKGROUND: Pouch complications after ileal pouch-anal anastomosis (IPAA) can result in morbidity and pouch loss. Recent reports describe success with redo IPAA. This study was conducted to assess the outcome of malfunctioning pouches treated by redo IPAA. METHODS: All patients undergoing redo IPAA between 1983 and 1999 were identified and clinical records studied. Redo IPAA was defined as an operation for malfunctioning pouch with pelvic dissection and disconnection, pouch revision, and reanastomosis. Analyzed were etiology, presentation, diagnostic modalities, surgical management, pouch loss, and outcome. Follow-up was obtained by telephone or mailed survey. RESULTS: Between 1983 and 1999, 650 IPAA procedures were performed, 6 (0.9%) of which required redo IPAA. Ten referred patients required redo IPAA. These 16 cases included 7 anastomotic disruptions, 3 pouch-vaginal fistulae, 2 recurrent polyps after stapled IPAA, 2 megapouches, 1 cuff abscess, and 1 straight pullthrough. All patients underwent redo IPAA with pouch salvage 100% in this series. Twelve had the original pouch repaired and 4 new pouches. Six patients (37%) had complications and outcome was acceptable with 7.8 stools per day and nighttime incontinence "rarely" or "never" in 7 patients. Eight described results as "good," 6 as "fair.". CONCLUSION: Redo IPAA can be performed with few complications, an acceptable outcome, and should result in low pouch loss.     

Lightning injuries

Lightning strikes may cause a constellation of injuries. Blunt head trauma, neurologic injury, and cardiac injury are common in these patients. In contrast to high-voltage electrocutions, blunt trauma after a lightning strike is common. Thorough evaluation of all organ systems is crucial. This report discusses mechanism of injury and describes initial evaluation and treatment of lightning strike victims.     

Isolation and characterization of murine cell surface components. I. Purification of milligram quantities of Thy-1.1

The Thy-l.1 molecule was isolated from the BW5147 murine lymphoblastoid cell line. The initial step in purification was the preparation of a crude plasma membrane fraction followed by acetone precipitation. The acetone pellet was solubilized using deoxycholate (DOC) and Thy-1.1 was purified by use of a Lens culinaris lectin affinity column and an AcA-34 gel filtration column. The purified glycoprotein with Thy-1.1 activity had a mol wt of approximately 25,000 daltons. The isolation of this molecule was effected by detecting Thy-I activity utilizing rabbit anti- mouse brain serum tested on rat thymocytes. Congenic anti-Thy-l.1 serum was ineffective in detecting Thy-l.1 after DOC solubilization. An antiserum prepared in rabbits to the purified Thy-1.1 was found to be cytotoxic to mouse and rat thymocytes. The cytotoxic activity of this antisera could be completely absorbed with AKR/Jax brain and thymus but was not absorbed by liver. In addition, AKR/Jax thymocytes totally absorbed all cytotoxic activity of the rabbit anti-purified Thy-1 serum for BW5147 cells suggesting that the cell line shares identical specificities with normal thymocytes. The purified Thy-1.1 molecule was able to totally absorb the cytotoxic activity of mouse congenic anti-Thy-1. These studies serve as a model for the isolation of other murine lymphoid cell surface components in quantities for detailed structural and functional analysis.