Assessing the influence of field- and GIS-based inquiry on student attitude and conceptual knowledge in an undergraduate ecology lab.

Combining field experience with use of information technology has the potential to create a problem-based learning environment that engages learners in authentic scientific inquiry. This study, conducted over a 2-yr period, determined differences in attitudes and conceptual knowledge between students in a field lab and students with combined field and geographic information systems (GIS) experience. All students used radio-telemetry equipment to locate fox squirrels, while one group of students was provided an additional data set in a GIS to visualize and quantify squirrel locations. Pre/postsurveys and tests revealed that attitudes improved in year 1 for both groups of students, but differences were minimal between groups. Attitudes generally declined in year 2 due to a change in the authenticity of the field experience; however, attitudes for students that used GIS declined less than those with field experience only. Conceptual knowledge also increased for both groups in both years. The field-based nature of this lab likely had a greater influence on student attitude and conceptual knowledge than did the use of GIS. Although significant differences were limited, GIS did not negatively impact student attitude or conceptual knowledge but potentially provided other benefits to learners.

Repeatability of a telephone questionnaire on cat-ownership patterns and pet-owner demographics evaluation in a community in Texas, USA.

The repeatability of a telephone questionnaire on cat-ownership patterns, demographics and attitudes towards homeless cats in a community was evaluated. Randomly selected households (n=100) within Caldwell, Texas, were included in the study. The response percentage was 84% (100/119) among those contacted and 75% (100/134) among all eligible respondents. Repeatability was measured by administering the same survey twice to the first 100 responding subjects, with an average (range) of 48 (25-64) days between interviews. The survey was initially administered from 6 June to 28 June 2005 and the follow-up survey was administered from 19 July to 11 August 2005. Repeatability for most cat-ownership characteristics was fair to good between the two interviews (kappa 0.47-0.82). Knowledge of companion animals and subject attachment to pet questions had good correlations between the two interviews (rsp 0.52 and 0.60, respectively). Subject-demographic questions had excellent repeatability (kappa 0.66-1.00).

Long-term results of metallic stents for benign biliary strictures.

BACKGROUND: Historically, surgical correction has been the treatment of choice for benign biliary strictures (BBS). Self-expandable metallic stents (MSs) have been useful for inoperable malignant biliary strictures; however, their use for BBS is controversial and their natural history unknown. HYPOTHESIS: To test our hypothesis that MSs provide only short-term benefit, we examined the long-term outcome of MSs for the treatment of BBS. Our goal was to develop a rational approach for treating BBS. DATA EXTRACTION: Between July 1990 and December 1995, 15 patients had MSs placed for BBS and have been followed up for a mean of 86.3 months (range, 55-120 months). The mean age of the patients was 66.6 years and 12 were women. Stents were placed for surgical injury in 5 patients and underlying disease in 10 patients (lithiasis, 7; pancreatitis, 2; and primary sclerosing cholangitis, 1). One or more MSs (Gianturco-Rosch "Z" for 4 patients and Wallstents for 11 patients) were placed by percutaneous, endoscopic, or combined approaches. We considered patients to have a good clinical outcome if the stent remained patent, they required 2 or fewer invasive interventions, and they had no biliary dilation on subsequent imaging. DATA SYNTHESIS: Metallic stents were successfully placed in all 15 patients, and the mean patency rate was 30.6 months (range, 7-120 months). Five patients (33%) had a good clinical result with stent patency from 55 to 120 months. Ten patients (67%) required more than 2 radiologic and/or endoscopic procedures for recurrent cholangitis and/or obstruction (range, 7-120 months). Five of the 10 patients developed complete stent obstruction at 8, 9, 10, 15, and 120 months and underwent surgical removal of the stent and bilioenteric anastomosis. Four of these 5 patients had strictures from surgical injuries. The patient who had surgical removal 10 years after MS placement developed cholangiocarcinoma. CONCLUSIONS: Surgical repair remains the treatment of choice for BBS. Metallic stents should only be considered for poor surgical candidates, intrahepatic biliary strictures, or failed attempts at surgical repair. Most patients with MSs will develop recurrent cholangitis or stent obstruction and require intervention. Chronic inflammation and obstruction may predispose the patient to cholangiocarcinoma.

Metastasis of hepatocellular carcinoma to the right colon manifested by gastrointestinal bleeding.

An 82-year-old black woman with a history of hepatocellular carcinoma presented with gastrointestinal bleeding. Barium enema and fibrocolonoscopy revealed a 4-cm polypoid mass at the level of the ascending colon with evidence of active bleeding. Biopsies of the lesion proved it to be metastatic hepatocellular carcinoma. Exploratory laparotomy revealed no further dissemination of the tumor, and the patient underwent an ileocolectomy. The serosal side of the colonic lesion was free from tumor, and there was no peritoneal implantation, direct extension, or lymph node involvement. This case represents an extremely rare presentation of metastatic hepatocellular carcinoma.

Management of bronchobiliary fistula as a late complication of hepatic resection.

Bronchobiliary fistula is an uncommon but remarkable complication after hepatic resection. The case reported illustrates the clinical presentation and preferred initial management of these fistulae. A 61-year-old white male underwent two wedge resections for colorectal metastases to the liver with removal of a portion of the right diaphragm. Four years later, he developed obstructive jaundice secondary to tumor recurrence in the porta hepatis, which required endoscopic stent placement, radiation, and chemotherapy. Almost 2 years later, he developed frank biliptysis. Percutaneous transhepatic cholangiography (PTC) revealed occlusion of the common hepatic duct stent and a bronchobiliary fistula. With adequate reestablishment of common duct drainage, the patient rapidly improved and was discharged free of symptoms. Bronchobiliary fistulae are rare complications of hepatic resection that can present from days to years after operation. Endoscopic retrograde cholangiopancreatography and PTC are the diagnostic studies of choice and offer the possibility of therapeutic intervention. Although large series in the literature emphasize the surgical management of bronchobiliary fistulae, the reoperative procedures tend to be complicated, with a significant morbidity and mortality. Nonsurgical interventions via endoscopic retrograde cholangiopancreatography or PTC are more recently notably successful when resolution of a distal biliary obstruction is accomplished. Only after aggressive attempts at nonoperative, interventional techniques have failed should operative approaches be entertained.

Hepatic artery chemoembolization for management of patients with advanced metastatic carcinoid tumors.

BACKGROUND: Patients with advanced metastatic carcinoid tumors who have disease progression despite conventional therapy are left with few therapeutic options. Hepatic artery chemoembolization (HACE) may play a role in palliating these patients' symptoms. METHODS: Fifteen patients with biopsy-proven advanced bilobar hepatic carcinoid metastases who demonstrated progression of symptoms and/or tumor size despite treatment with somatostatin analogues were treated with intra-arterial chemotherapy and HACE to determine efficacy and safety. Five days of intra-arterial 5-fluorouracil (1 g/m2) were followed by HACE with adriamycin (60 mg), cisplatin (100 mg), mitomycin C (30 mg), and polyvinyl alcohol (Ivalon); 200 micron to 710 micron). Patients were continued on octreotide at the same dose (150 to 2000 microg subcutaneous q 8 hours) before, during, and after the procedure. RESULTS: Efficacy of treatment was assessed by comparing pretreatment and 3-month clinical, laboratory, radiographic, and quality of life parameters. Symptoms were improved in 8 of 12 patients who had diarrhea, 7 of 12 who had flushing, 9 of 12 who had abdominal pain, and in 4 of 7 who had malaise. Elevated tumor markers decreased in all patients. Biochemical markers (mean +/- SE) at 3 months decreased by 60% +/- 6% for 5-HIAA, 75% +/- 10% for chromogranin A and 50% +/- 7% for neuron-specific enolase. Tomographic assessment revealed tumor liquefaction in 10 of 13 patients. The Karnofsky performance status improved from a mean of 66 +/- 2 to 84 +/- 2 (P <0.001). Median follow-up was 16 months, with 13 deaths occurring from 1 week to 71 months after treatment. CONCLUSIONS: Hepatic artery chemoembolization improves symptoms of carcinoid syndrome, has a high tumor response rate, and improves short-term quality of life in this group of patients with advanced hepatic carcinoid disease.

Transarterial chemoembolization is a safe treatment for unresectable hepatic malignancies.

Acute liver failure has been reported as a frequent complication of transarterial chemoembolization (TACE). We prospectively evaluated the adverse effects and biochemical changes of TACE. From 10/95 to 9/96, 35 patients with hepatic malignancies were evaluated for TACE. Fifteen patients (9 male and 6 female) received 23 treatments. Ten of 15 patients had hepatocellular carcinoma, and 5 had metastatic tumors. Treatment exclusion criteria included advanced liver disease, hepatic vascular thrombosis, and severe comorbidity. TACE consisted of intra-arterial infusion of a mixture of doxorubicin, cisplatin, and mitomycin followed by embolization. Clinical symptoms and laboratory studies were monitored following treatment. Technical success was achieved in all patients. Adverse symptoms were transient, and most resolved within 1 week. Changes in hepatic, renal, and hematologic function were temporary and returned to pre-TACE levels by 1 month. None developed acute liver failure. The mean hospital stay was 3 days. Ten of 13 patients had a significant decrease in baseline tumor markers. The actual survival was 93 per cent with a median follow-up of 10 months. TACE can be performed safely in patients with hepatic tumors. The adverse effects can be anticipated and easily managed.

A model for the extended studies of hepatic hemodynamics and metabolism in swine.

To our knowledge postoperative hepatic hemodynamics and hepatic metabolism have not been fully studied on a long-term basis. Our goal was to develop a large animal model that would permit the measurement of hepatic blood flow (BF), perihepatic pressures (P), and hepatic metabolism in a long-term setting. Catheters were inserted into the jugular vein, carotid artery, pulmonary artery, hepatic vein, and portal vein (PV) of 27 commercially bred pigs; ultrasonic transit time flowmeter probes were placed around the hepatic artery and PV. Daily postoperative measurements of jugular vein P, carotid artery P, pulmonary artery P, hepatic vein P, and PVP, as well as hepatic artery BF and PVBF, were recorded for 20 days. Hepatic carbohydrate metabolism was assessed by arteriovenous difference techniques. Jugular vein P, pulmonary artery P, hepatic vein P, PVP, and heart rate reached steady-state values during the first week, with a mean +/- SEM of 1.0 +/- 0.3 mm Hg for jugular vein P, 21.4 +/- 2.1 mm Hg for pulmonary artery P, 4.3 +/- 0.4 mm Hg for HVP, 7.8 +/- 0.5 mm Hg for PVP, and 116 +/- 4 beats per minute for heart rate. Mean carotid artery P increased from 65 +/- 3 mm Hg during surgery to 94 +/- 2 mm Hg on postoperative day 1 (P < 0.001) and to a mean 101 +/- 2 mm Hg thereafter. Total hepatic BF reached a steady-state value of 1,132 +/- 187 ml/min by postoperative day 7 (P = 0.19). Over week 1 hepatic artery BF measured as a percentage of total hepatic BF decreased from 35.0 +/- 3.0% to 15.5 +/- 2.7%, and PVBF increased from 65.0 +/- 3.0% to 84.5 +/- 2.7% (P < 0.005); both variables were steady thereafter. In the hemodynamic steady state the net hepatic balances of glucose, lactate, glycerol, and alanine in 5 pigs were 9.9 +/- 4.0, -4.2 +/- 0.4, -2.3 +/- 1.1, and -0.68 +/- 0.22 micromol/kg per min respectively. The net gut (portal-drained viscera) balances of glucose, lactate, alanine, and glycerol were -2.0 +/- 2.5, 1.1 +/- 0.5, 0.73 +/- 0.18, and -0.69 +/- 0.19 micromol/kg per min respectively. Thus, a reliable large animal model was developed to study acute and chronic hepatic hemodynamics and metabolism.

Transjugular intrahepatic portosystemic shunt: efficacy for the treatment of portal hypertension and impact on liver transplantation.

Variceal bleeding (VB) and ascites refractory to diuretics (RA) represent a significant cause of morbidity and mortality in patients with portal hypertension. Transjugular intrahepatic portosystemic shunts (TIPS) have been used effectively in patients with these complications, especially those individuals awaiting orthotopic liver transplantation (OLT). From April 1992 to July 1995, 41 adult patients underwent an attempt at TIPS placement for refractory VB or ascites at Cedars-Sinai Medical Center. Technical success was achieved in 37 of 41 cases (90.3%) with only two technical complications. Immediate control of hemorrhage and significant improvement of ascites was obtained in 91.9% and 83.5% of the patients, respectively. Six patients (16.2%) died within a week of TIPS placement due to uncontrollable ascites and multiorgan failure. Four of 31 patients (12.9%) developed mild to moderate grades of hepatic encephalopathy that was controlled with lactulose. Rebleeding from recurrent portal hypertension was noted in 5 of 31 cases (16.1%). Shunt stenosis or occlusion was seen in 7 of 31 cases (22.6%) at an average of 6.3 months following TIPS placement. Six patients underwent OLT within an average of 87 days after TIPS. These results indicate that TIPS appears to be an effective method for treatment of refractory VB and RA, especially for patients who are poor candidates for a surgical shunt or awaiting OLT. However, TIPS may not be considered a definitive solution for all patients with portal hypertension because of its current rate of shunt occlusion or stenosis.

Enhanced oral cyclosporine absorption with water-soluble vitamin E early after liver transplantation.

We evaluated the effect of Liqui-E, a water-soluble vitamin E preparation, on cyclosporin A (CyA) whole blood concentration in liver transplant recipients, and its impact on the cost of CyA. Patients were 26 liver transplant recipients (19 adults, 7 children) who were unable to achieve and maintain therapeutic CyA whole blood concentrations with the standard recommended oral daily dose in the early post-transplant period. Liqui-E 6.25 IU/kg orally was administered with CyA every 12 hours (median time of starting Liqui-E day 14.5). With Liqui-E, the daily oral CyA requirements (mean +/- SD) were decreased in adults from 22.6 +/- 8.9 to 16.2 +/- 7.3 mg/kg/day (p < 0.001) and in children from 78.6 +/- 34.1 to 53.7 +/- 35.0 mg/kg/day (p < 0.02); intravenous administration of CyA was unnecessary. The CyA trough concentrations (mean +/- SD) before and after Liqui-E were 670 +/- 186 and 1012 +/- 216 ng/ml, respectively, in adults (p < 0.001) and 732 +/- 187 and 1052 +/- 166 ng/ml, respectively, in children (p < 0.01). When given with Liqui-E, the daily cost of CyA decreased by 26% in both adults and children. No clinical or biochemical evidence of Liqui-E toxicity was observed. Thus its administration in the early post-transplantation period can enhance CyA absorption in adults and children who are unable to achieve adequate whole blood concentrations with the usual recommended oral dosages. In addition, a significant cost saving can be realized by coadministration.

Hepatic resection for malignancy in the elderly.

Although elderly patients are accounted for in all large series of major hepatic resections, the role of age as a determinant of outcome remains unclear. At Cedars-Sinai Medical Center, we review a series of 20 major hepatectomies for neoplasia performed in patients older than 66 years of age (4 of them > or = 80 years old) over a 5-year period. A retrospective comparison was conducted with a group of 22 hepatectomies for malignancy performed in 20 patients younger than 59 years of age during the same time period. The younger group had a significantly greater degree of liver resected (12 trisegmentectomies vs 3). Although one operative death (5% mortality) was observed in the elderly group, no statistically significant difference was noted, when compared to the younger group (Chi-square, P = 0.48). Likewise, no significant difference in the complication rate (20% vs 33%) was noticed (Chi-square, P = 0.8). Severe postoperative liver dysfunction was present in 2 cases (10%) in the elderly group and one (4%) in the younger group. These patients underwent a right trisegmentectomy (TS). Nine patients from each group were resected without red blood cell transfusion. We conclude that major hepatic resection in elderly patients without severe comorbid disease is a safe procedure that is not associated with an increased perioperative morbidity or mortality rate.

Resection of primary hepatic malignant fibrous histiocytoma, fibrosarcoma, and leiomyosarcoma.

Four patients had resection for primary hepatic sarcoma: one with malignant fibrous histiocytoma (MFH), two with poorly differentiated fibrosarcoma, and one with leiomyosarcoma. Age ranged from 40 to 69 years. One patient had a cousin and a grandmother who had died of hepatic tumors. At presentation, all patients had pain; one had tumor rupture, and one had mental changes and hypoglycemia. None had hepatitis or cirrhosis. Results of laboratory evaluation were nonspecific, including normal carcinoembryonic antigen and alpha-fetoprotein levels. Computed tomography showed hypodense masses with enhancement. Angiography showed a hypervascular mass in three patients and an avascular mass in the patient with MFH. Despite large tumors (8 to 32 cm), portal and hepatic veins were not invaded. The pattern of vascularization and lack of venous invasion helps differentiate primary hepatic sarcomas from hepatocellular carcinoma, especially in noncirrhotic patients. All patients had extensive hepatic resections, with one operative death. Immunohistochemical stains of the tumors were positive for vimentin but negative for epithelial markers, differentiating these lesions from other hepatic tumors. The patient with MFH died with recurrence at 10 1/2 months. The patient with the ruptured fibrosarcoma had a second resection and chemotherapy, but died with recurrence at 3 years. The patient with the leiomyosarcoma had a second resection and was disease free at 4 years. Resection of primary hepatic sarcoma is warranted, with potential survival measured in years.

Role of computed tomographic scans in the staging of esophageal and proximal gastric malignancies.

In order to determine the accuracy of computed tomographic (CT) scanning, CT scan results were compared with operative and pathologic findings in 45 patients with esophageal and proximal gastric malignancies. CT scans were evaluated with respect to nodal metastases, hepatic metastases, and adjacent spread. Eight patients did not undergo surgery because of advanced disease noted on the CT scan. Of the remaining 37 patients, sensitivity of CT for all 3 parameters was less than 60%, whereas the specificity was greater than 90%. The positive predictive value was greater than 90% for nodal metastases and adjacent spread and 67% for hepatic metastases. The negative predictive value was less than 40% for nodal metastases and adjacent spread and 90% for hepatic metastases. For esophageal and proximal gastric malignancies, CT is useful in identifying advanced disease and in predicting resectability. In less advanced cases, CT is not sensitive, and its negative predictive value is poor with regard to local and lymphatic spread. CT scanning is useful to stage the most advanced cases but because of limited accuracy should be combined with other diagnostic studies when accurate staging is required.

Fibrosing cytolytic liver failure secondary to recurrent hepatitis B after liver transplantation.

Four patients who underwent transplantation for hepatitis B virus-related liver disease developed rapidly progressive liver failure attributable to recurrent hepatitis B disease typified by hyperbilirubinemia and distinctive hepatocyte ballooning and progressive fibrosis consistent with recently reported fibrosing cholestatic hepatitis. Among these four patients, the mean interval from transplantation to redocumentation of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) was 5 months, to development of malaise and jaundice 6 months, to histological diagnosis 7 months, and to graft failure 8 months. The only patient who underwent retransplantation had accelerated recurrence of the same syndrome with biopsy documentation 1 month later and graft failure 2 months later. Distinctive histological features included confluent hepatocellular ballooning and progressive periportal fibrosis followed by lobular collapse over 4-6 weeks without significant inflammation. Immunohistochemical staining showed marked HBsAg and hepatitis B core antigen (HBcAg) immunoreactivity. The rapid development of cytolytic hepatocellular necrosis and lobular collapse with prominent HBcAg immunoreactivity without significant inflammation suggests a cytolytic rather than immune pathogenesis for this unique and devastating form of recurrent hepatitis B that might better be termed "fibrosing cytolytic hepatitis."

Management of biliary complications after liver transplantation.

Biliary tract complications after liver transplantation are common, and the evaluation of newer treatment options compared with standard surgical treatment is important. In 62 liver transplants performed in 55 adult patients, the biliary tract was reconstructed with choledochocholedochostomy (CC) in 52 (84%) and Roux-en-Y choledochojejunostomy (RYCJ) in 10 (16%). Seventeen biliary tract complications occurred in 16 patients (29%). The incidence of complications was the same after CC and RYCJ. Eight complications (47%) occurred within the first month and nine (53%) thereafter. Only 6 of 17 (35%) biliary tract complications required operation. One patient died of a biliary tract complication. No other allografts were lost due to biliary tract complications. Four patients transplanted at other centers were also treated, for a total of 21 biliary tract complications. Overall, there were nine bile leaks, eight bile duct strictures, two Roux loop hemorrhages, one choledocholithiasis, and one ampullary dyskinesia. Temporary or permanent stents were used successfully in seven of eight strictures. Five bile leaks were managed without operation. Nonsurgical management is appropriate for a selected majority of patients with late bile leaks, biliary tract strictures, or choledocholithiasis after liver transplantation.