Factors affecting performance on the American Board of Surgery in-training examination.

BACKGROUND: Surgical programs use the American Board of Surgery In-Training Examination (ABSITE) in several ways, including for promotion and retention decisions. The purpose of this study was to identify the combination of factors that explain residents' successful performance on the ABSITE. METHODS: Fifty-one surgical residents completed questionnaires, and information was gathered about their previous ABSITE performance, anxiety, probationary status, amount of study, amount of sleep before examination, confidence, and attendance at conference. RESULTS: An analysis of the data for those with experience taking the examination (n = 34) indicated that the combination of conference attendance (26.3%), previous performance (16.5%), probationary status (10.4%), amount of sleep (9.8%), and amount of study (8%) were significant in explaining a total of 71% of the variance in ABSITE scores. Amount of study (+0.32, P = 0.011), confidence (+0.36, P = 0.005), and conference attendance (+0.51, P = 0.001) were significantly correlated with ABSITE performance. CONCLUSIONS: Several factors contribute to residents' successful ABSITE performance. These findings may lead to improved examination performance and application of knowledge, both during residency and throughout their career.

Factors affecting improvement on the American Board of Surgery In-Training Exam (ABSITE).

BACKGROUND: American Board of Surgery In-Training Exam (ABSITE) performance can be used to assess resident knowledge and to evaluate surgical curriculum. To determine factors that lead to improved resident ABSITE performance, a prospective study was performed. MATERIALS AND METHODS: Thirty-four surgical residents in Program Years 2-5 completed pre- and a post-ABSITE questionnaires about their anxiety, self-efficacy, physical preparation, and academic preparation for the ABSITE. Department records were used to determine resident probationary status and conference attendance. A preliminary analysis of ABSITE scores indicated a significant improvement between 1998 and 1999 percentile scores (paired t = -2. 25, P = 0.03; m = 11.9, SD = 30.5, median = 7). An improvement in percentile rank score was calculated and used as the dependent variable in a stepwise regression analysis. The following served as independent variables: previous exam performance, anxiety, probationary status, amount of sleep before exam, confidence to score in the 25th and the 50th percentiles, and attendance at the three conferences rated most valuable by the residents. RESULTS: Results of the regression analysis demonstrate that all factors account for 62.3% of the variance in improvement scores. A stepwise analysis indicated that the combination of attendance (40.2%) and previous performance (18.3%) was significant in explaining 58.5% of the variance in improvement scores. Furthermore, Pearson's correlations indicated that probationary status (+.58, P = 0.001), anxiety (+0.53, P = 0.001), amount of study (+0.61, P = 0.001), past ABSITE performance (-0.60, P = 0.001), and conference attendance (+0. 56, P = 0.001) were correlated with ABSITE improvement. CONCLUSIONS: This study demonstrates that resident individual effort, past ABSITE performance, and academic conference attendance have led to resident ABSITE improvement.

Surgical approach to adrenal neoplasms: laparoscopic versus open adrenalectomy.

There are a number of different approaches available to surgically remove the adrenal gland. These can be broadly classified into two general categories, open and laparoscopic. There is no one best method for all patients. Surgeons, skilled in all aspects of adrenal surgery, should choose an approach for adrenalectomy based on patient and tumor related factors. Once advantages and disadvantages of a specific procedure, with these factors in mind, are weighed, the best approach for the individual patient should be chosen.

Intrabiliary growth of metastatic colonic adenocarcinoma: a pattern of intrahepatic spread easily confused with primary neoplasia of the biliary tract.

Because of its propensity to spread along epithelial surfaces, colonic adenocarcinoma can mimic other neoplasms. For example, colonic adenocarcinoma can grow along the surface of the urinary bladder and can simulate primary bladder neoplasia, and metastatic colonic adenocarcinoma can grow along alveolar walls and can mimic primary lung neoplasia. Intraepithelial spread along bile ducts, however, is not a well-recognized behavior of hepatic metastases. Indeed, dysplastic change in the epithelium lining the biliary tract is sometimes used to discriminate primary biliary neoplasms from metastatic adenocarcinoma. We report on eight cases of colonic adenocarcinoma metastatic to the liver that demonstrated prominent spread throughout the biliary tree along intact basement membranes. Morphologically, this pattern closely resembled high-grade dysplasia (i.e., carcinoma in situ) of the extrahepatic and intrahepatic bile ducts. Clinically, two of the tumors were mistaken for primary biliary neoplasia because of the common radiologic finding of intrabiliary masses with distended bile ducts. A definite diagnosis of metastatic carcinoma was established by careful attention to the medical history, thorough evaluation of the morphologic features, and histologic comparison with the primary colon cancer. For patients with a history of colonic adenocarcinoma, consideration of a liver metastasis is appropriate even when certain histologic and radiographic features point to a neoplasm of biliary origin.

The effect of partial portal decompression on portal blood flow and effective hepatic blood flow in man: a prospective study.

With the advent of transjugular intrahepatic porta-systemic stent shunt and the wider application of the surgically placed small diameter prosthetic H-graft portacaval shunt (HGPCS), partial portal decompression in the treatment of portal hypertension has received increased attention. The clinical results supporting the use of partial portal decompression are its low incidence of variceal rehemorrhage due to decreased portal pressures and its low rate of hepatic failure, possibly due to maintenance of blood flow to the liver. Surprisingly, nothing is known about changes in portal hemodynamics and effective hepatic blood flow following partial portal decompression. To prospectively evaluate changes in portal hemodynamics and effective hepatic blood flow brought about by partial portal decompression, the following were determined in seven patients undergoing HGPCS: intraoperative pre- and postshunt portal vein pressures and portal vein-inferior vena cava pressure gradients, intraoperative pre- and postshunt portal vein flow, and pre- and postoperative effective hepatic blood flow. With HGPCS, portal vein pressures and portal vein-inferior vena cava pressure gradients decreased significantly, although portal pressures remained above normal. In contrast to the significant decreases in portal pressures, portal vein blood flow and effective hepatic blood flow do not decrease significantly. Changes in portal vein pressures and portal vein-inferior vena cava pressure gradients are great when compared to changes in portal vein flow and effective hepatic blood flow. Reduction of portal hypertension with concomitant maintenance of hepatic blood flow may explain why hepatic dysfunction is avoided following partial portal decompression.

Mixed-function oxidase activity in sepsis.

Hepatic dysfunction is a major contributor to death in multiple organ system failure. To evaluate whether this dysfunction increases with the length of sepsis, we studied the effect of fulminant CLP peritonitis with hyperoxia on mixed-function oxidase-MFO (cytochrome P450 content and activity) and lipid peroxidation in rat livers. Livers were harvested at 18, 21, 24, and 27 hr, homogenized, and microsomal fractions prepared. Cytochrome P450 concentration was determined by assay and P450 activity was determined by the metabolism of ethoxyresorufin and ethoxycoumarin. Lipid peroxidation was estimated by measuring malondialdehyde content. Septic rats showed decreases in P450 levels and activity, which worsened with duration of sepsis. These decreases were partially lessened by hyperoxia. Although there was a trend toward increased lipid peroxidation, this effect was not statistically significant. This study suggests that while MFO content and activity decrease with sepsis, these decreases do not appear to be related to the production of oxygen-derived free radicals. Furthermore, hyperoxia actually appears to have a protective role in this instance.

The identification and mapping of melanoma regional nodal metastases: minimally invasive surgery for the diagnosis of nodal metastases.

The most controversial part of melanoma surgical care involves the role of elective lymph node dissection (ELND). Whereas proponents cite retrospective studies demonstrating the ability to control regional metastases and more accurate staging, opponents cite the unnecessary morbidity of a complete node dissection for the majority of patients. The technology of sentinel node mapping and selective lymphadenectomy, defined as the identification and removal of the first node into which the primary melanoma drains, may revolutionize melanoma care. If the sentinel node is negative, then theoretically the remainder of the nodes should also be negative (no "skip" metastases), and a complete lymphadenectomy would not be required to control occult nodal disease. The location of the sentinel node may be variable in the lymphatic basin. Ideally, the surgeon needs a map of the position of the sentinel node in reference to the other nodes in the basin in order to do the procedure under local anesthesia with small incisions. In this way, patients are subjected to minimal morbidity and the procedure can be performed as an out-patient. Twenty-nine patients with clinically negative nodes and melanomas greater than 0.76 mm in thickness were judged to be candidates for ELND. Preoperative lymphoscintigraphy in two planes was used to mark the sentinel node, and the patients were taken to the operating room for intraoperative lymphatic mapping and sentinel node biopsy followed by complete dissection.(ABSTRACT TRUNCATED AT 250 WORDS)

HPAC, a new human glucocorticoid-sensitive pancreatic ductal adenocarcinoma cell line.

A new human pancreatic cancer (HPAC) cell line was established from a nude mouse xenograft (CAP) of a primary human pancreatic ductal adenocarcinoma. In culture, HPAC cells form monolayers of morphologically heterogenous, polar epithelial cells, which synthesize carcinoembryonic antigen, CA 19-9, CA-125, cytokeratins, antigens for DU-PAN-2, HMFG1, and AUA1, but do not express chromogranin A or vimentin indicative of their pancreatic ductal epithelial cell character. In the presence of serum, HPAC cell DNA synthesis was stimulated by insulin, insulin growth factor-I, epidermal growth factor, and TGF-α but inhibited by physiologic concentrations of hydrocortisone and dexamethasone. Dose-dependent inhibition of DNA synthesis was limited to steroids with glucocorticoid activity. The inhibitory effect of dexamethasone was abolished by the glucocorticoid antagonist RU 384862 Binding of [3H] dexamethasone to cytosolic proteins was specific and saturable at 4 degrees C. Scatchard analysis of binding data demonstrated a single class of high-affinity binding sites (K(d) = 3.8 ± 0.9 nM; B(max) = 523 ± 128 fmol/mg protein). Western blot analysis revealed a major protein band that migrated at a M(r) of 96 kDa. Northern blot analysis identified an mRNA of approximately 7 kilobases which hybridized with a specific glucocorticoid receptor complementary-DNA probe (OB7). These findings support a role for glucocorticoids in the regulation of human malignant pancreatic cell function.

Hepatic function after porto-systemic shunt.

Advanced hepatic injury can be identified by the appearance of jaundice, coagulopathy, or encephalopathy but these conditions are late, irreversible findings and represent the end stage of a long insidious process. Currently available methods for assessing "liver function" (SGOT, SGPT, GGT, LDH, etc.) do not actually measure liver function. In this study we prospectively evaluated "true" liver function in patients undergoing porto-systemic shunt. Effective hepatic blood flow [low dose galactose clearance (EHBF)], hepatocyte transport (theophylline levels at 24 hr), and hepatic conjugation ability [acetaminophen metabolism to its glucuronide and sulfate conjugates ( (S + G)/A) and acetaminophen remaining at 24 hr (A24)] were measured in normal males (NL) and in patients pre- and post-8-mm H-graft portacaval shunt (PCS). All data are means +/- SEM, analyzed by Student's t test, and significance was accepted if P less than 0.05. There were no significant differences in EHBF even after PCS. Hepatocyte transport was decreased in pre-op (1.43 +/- 0.16 vs 0.74 +/- 0.08) and post-op (1.79 +/- 0.34) PCS patients. Hepatic conjugating ability was also decreased in pre-op PCS patients [A24 was increased (0.24 +/- 0.11 vs 0.01 +/- 0.01) while the ratio of conjugation products to acetaminophen remained the same]. The ability of the liver to conjugate substrate was severely compromised postoperatively [A24 - 1.27 +/- 0.67, (S + G)/A - 1.19 +/- 0.34]. We believe that changes in liver function can be accurately measured using these noninvasive methods, and in using these methods we have identified altered hepatocyte transport and conjugating ability in patients undergoing porto-systemic shunt surgery.

Atrial natriuretic factor: a possible new gastrointestinal regulatory peptide.

Although associated primarily with the cardiovascular system, atrial natriuretic factor (ANF) has been found to increase the magnitude of duodenal contractions and may play a role in salt and water absorption across gastrointestinal epithelium. Because secretory diarrhea and increased peristalsis are commonly associated with conditions related to hypergastrinemia, we examined an animal model of hypergastrinemia (fundusectomy) to evaluate a possible role for ANF. Sprague-Dawley rats underwent either fundusectomy or sham operation. Circulating levels of gastrin (1085 +/- 105 vs 59 +/- 5 pg/ml), ANF (209 +/- 50 vs 59 +/- 10 pg/ml), and pro-ANF 1-98 (786 +/- 80 vs 599 +/- 49 pg/ml) were elevated significantly 3 months after fundusectomy versus control animals. The increased levels of ANF and pro-ANF 1-98 correlated with the increased gastrin levels (p less than 0.05). Tissue content of ANF and pro-ANF 1-98 were determined at sequential sites in the stomach and small intestine. In normal rats ANF concentrations were greatest in the small intestine; pro-ANF 1-98 content was similar in all tissues except ileum (increased). In rats that underwent fundusectomy, ANF and pro-ANF 1-98 were markedly increased in duodenum compared with all other tissues. Only duodenum showed a difference in peptide levels between normal rats and rats that underwent fundusectomy, (ANF, 1.5 +/- 0.5 vs 16.7 +/- 2.3 ng/gm; pro-ANF 1-98, 0.6 +/- 0.3 vs 51.2 +/- 36.1 ng/gm). Circulating ANF and pro-ANF 1-98 are increased in rats that have undergone fundusectomy. Our results suggest that duodenum may be the source of these increased levels.

Posttranslational gastrin processing depends on tumor morphology.

Extracellular matrices have recently been demonstrated to alter cell morphology in culture. Altered cell morphology has been associated with changes in gene transcription and translation, but it is not known whether it also affects posttranslational processing. Using tyrosine-O-sulfation as a marker of processing, we studied the effects of various substrates on biologically active gastrin (IRG) production and sulfation in gastrin-containing tumor cells (GT cells). Dispersed GT cells were plated onto different substrates and then incubated. Culture media from days 4, 7, and 28 were assayed with specific antibodies that recognize total IRG and nonsulfated IRG. Cells cultured on plastic and dried films of laminin, collagen, and Matrigel (Collaborative Research Inc., Lexington, Mass.) flattened and formed monolayers of GT cells. Cells cultured on a porous membrane and hydrated gels of collagen and Matrigel did not flatten but formed spheroids of GT cells. The monolayer cultures showed an increase in sulfation with time but a decrease in IRG production. The spheroid cultures maintained a constant level of sulfation over time and, with the exception of Matrigel (gel), also showed a decrease in IRG production. These results indicate that the level of sulfation was unchanged from that of the original tumor when cells were grown in spheroids but increased when cultured as monolayers. It appears that alteration of the cellular milieu alters colony morphology, which in turn alters gastrin processing.