Bone morphogenetic protein 4 expressed in esophagitis induces a columnar phenotype in esophageal squamous cells

BACKGROUND & AIMS

Barrett's esophagus (BE) is a metaplastic condition in which normal squamous esophageal epithelium is replaced by columnar epithelium. It is proposed that one of the possible mechanisms is dedifferentiation of squamous epithelium into columnar epithelium. The pathophysiology through which this metaplasia occurs is unknown. A recent study by serial analysis of gene expression showed that bone morphogenetic protein 4 (BMP-4) is uniquely expressed in BE. In this study, the role of the BMP pathway in the metaplastic transformation of normal squamous cells into columnar cells was examined.

METHODS

Tissues from patients with esophagitis and BE and in an esophagitis-BE rat model were examined for the activation of the BMP pathway. Short-term cultures of primary normal squamous esophageal cells were treated with BMP-4, and cell biological changes were examined by Western blot analysis, immunohistochemistry, and microarrays.

RESULTS

In both human and rat tissues, the BMP pathway proved to be activated in esophagitis and BE. Upon incubation of squamous cell cultures with BMP-4, the cytokeratin expression pattern showed a shift that was consistent with columnar epithelium. Involvement of the BMP pathway was suggested by up-regulation of Phosphorylated-Smad 1/5/8 (P-Smad 1/5/8) that was effectively blocked by Noggin, a BMP antagonist. Comparison of the gene expression profiles of squamous cells, BMP-4-treated squamous cells, and BE cells showed a significant shift in the profile of the BMP-4-treated squamous cells toward that of the cultured BE cells.

CONCLUSIONS

These results suggest that the BMP pathway could play a role in the transformation of normal esophageal squamous cells into columnar cells.

Factors associated with increased survival after photodynamic therapy for cholangiocarcinoma

BACKGROUND & AIMS

Recent studies have shown a survival advantage using photodynamic therapy (PDT) in patients with unresectable cholangiocarcinoma. Factors associated with increased survival after PDT are unknown.

METHODS

Twenty-five patients with cholangiocarcinoma who were treated with PDT at the Mayo Clinic Rochester from 1991 to 2004 were studied. Porfimer sodium (2 mg/kg) was administered intravenously to patients with Bismuth type I (3 patients), type III a/b (13 patients), and type IV (9 patients) tumors. Forty-eight hours later, PDT was administered using a 1.5- to 2.5-cm diffusing fiber that was advanced across the tumor by either retrograde (20 patients) or percutaneous (5 patients) cholangiography. Laser light was applied for a total energy of 180 J/cm2 in 1-3 applications. Patients received PDT treatments every 3 months. Plastic biliary stents (10-11.5 F) were inserted to decompress the biliary system after PDT. Survival analysis was performed using Kaplan-Meier curves and Cox proportional hazards models.

RESULTS

Patients were 64 (standard error of the mean, +/-2.6) years of age; 20 (80%) were men. The median overall survival period was 344 days. The median survival period after PDT was 214 days. The 1-year survival rate was 30%. On multivariate analysis, the presence of a visible mass on imaging studies (hazard ratio, 3.55; 95% confidence interval, 1.21-10.38), and increasing time between diagnosis and PDT (hazard ratio, 1.13; 95% confidence interval, 1.02-1.25) predicted a poorer survival rate after PDT. A higher serum albumin level (hazard ratio, 0.16; 95% confidence interval, 0.04-0.59) predicted a lower mortality rate after PDT.

CONCLUSIONS

Patients with unresectable cholangiocarcinoma without a visible mass may benefit from earlier treatment with PDT.

Prospective study of bacteremia and complications With EUS FNA of rectal and perirectal lesions

BACKGROUND & AIMS

Recent studies showed that endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) is a low-risk procedure for causing bacteremia and infectious complications when sampling solid lesions of the upper gastrointestinal (GI) tract. As a result, antibiotics are not recommended for prophylaxis against endocarditis. Our aim was to prospectively evaluate the risk of bacteremia and other infectious complications in patients undergoing EUS FNA of lower GI tract lesions.

METHODS

Patients referred for EUS FNA of lower GI tract lesions were considered for enrollment. Patients were excluded if there was an indication for preprocedure antibiotic administration based on American Society for Gastrointestinal Endoscopy guidelines, had taken antibiotics within the prior 7 days, or if they had a cystic lesion. Blood cultures were obtained immediately before the procedure, after flexible sigmoidoscopy/radial EUS, and 15 minutes after EUS FNA.

RESULTS

One hundred patients underwent a total of 471 FNAs (mean, 4.7 FNAs/patient; range, 1-10 FNAs/patient). Blood cultures were positive in 6 patients. Cultures from 4 patients (4.0%, 95% confidence interval, 1.6%-9.8%) grew coagulase-negative Staphylococcus (n = 2), Peptostreptococcus stomatis (n = 1), or Moraxella (n = 1), which were considered contaminants. Two patients (2.0%, 95% confidence interval, 0.6%-7%) developed bacteremia: Bacteroides fragilis (n = 1) and Gemella morbillorum (n = 1). No signs or symptoms of infection developed in any patient.

CONCLUSIONS

EUS FNA of solid lesions in the lower GI tract should be considered a low-risk procedure for infectious complications that does not warrant prophylactic administration of antibiotics for the prevention of bacterial endocarditis.

Long-term survival following endoscopic and surgical treatment of high-grade dysplasia in Barrett's esophagus

BACKGROUND & AIMS

Photodynamic therapy (PDT) for high-grade dysplasia (HGD) in Barrett's esophagus is a Food and Drug Administration-approved alternative to esophagectomy. Critical information regarding overall survival of patients followed up long-term after these therapies is lacking. Our aim was to compare the long-term survival of patients treated with PDT with patients treated with esophagectomy.

METHODS

We reviewed records of patients with HGD seen at our institution between 1994 and 2004. PDT was performed 48 hours following the intravenous administration of a photosensitizer using light at 630 nm. Esophagectomy was performed by either transhiatal or transthoracic approaches by experienced surgeons. We excluded all patients with evidence of cancer on biopsy specimens. Vital status and death date information was queried using an institutionally approved Internet research and location service. Statistical analysis was performed using Kaplan-Meier curves and Cox proportional hazards ratios.

RESULTS

A total of 199 patients were identified. A total of 129 patients (65%) were treated with PDT and 70 (35%) with esophagectomy. Overall mortality in the PDT group was 9% (11/129) and in the surgery group was 8.5% (6/70) over a median follow-up period of 59 +/- 2.7 months for the PDT group and 61 +/- 5.8 months for the surgery group. Overall survival was similar between the 2 groups (Wilcoxon test = 0.0924; P = .76). Treatment modality was not a significant predictor of mortality on multivariate analysis.

CONCLUSIONS

Overall mortality and long-term survival in patients with HGD treated with PDT appears to be comparable to that of patients treated with esophagectomy.

Endoscopic therapy in patients with Barrett's esophagus and portal hypertension

BACKGROUND

Endoscopic mucosal resection has been used to stage and treat early neoplasia in Barrett's esophagus. The ability to do this in the setting of portal hypertension has not been reported.

OBJECTIVE

Our purpose was to describe the feasibility and efficacy of endoscopic mucosal resection in patients with portal hypertension and Barrett's esophagus.

DESIGN

Retrospective case series.

SETTING

Two tertiary referral centers.

PATIENTS

Patients with Barrett's esophagus and high-grade dysplasia or adenocarcinoma in the setting of portal hypertension.

INTERVENTION

Endoscopic mucosal resection of endoscopically visible lesions.

MAIN OUTCOME MEASUREMENTS

Complete resection of neoplastic lesion, lack of variceal bleeding.

RESULTS

Four patients were treated with endoscopic mucosal resection a total of 5 times. Endoscopic mucosal resection was successfully performed without significant GI bleeding.

LIMITATIONS

This preliminary case series describes feasibility of the procedure. Whether this can be generalized remains to be determined, although it may be an option in poor surgical candidates.

CONCLUSIONS

Endoscopic mucosal resection appears to be relatively safe in selected patients with portal hypertension and Barrett's esophagus. Further studies are needed to confirm these findings.

Balloon-based, circumferential, endoscopic radiofrequency ablation of Barrett's esophagus: 1-year follow-up of 100 patients

OBJECTIVE

To assess the dose-response, safety, and efficacy of circumferential endoscopic ablation of Barrett's esophagus (BE) by using an endoscopic balloon-based ablation device (HALO360 System).

DESIGN

This study was conducted in 2 serial phases (dosimetry phase and effectiveness phase) to evaluate a balloon-based ablation device that delivers a pre-set amount of energy density (J/cm2) to BE tissue. The dosimetry phase evaluated the dose-response and the safety of delivering 6 to 12 J/cm2. The effectiveness phase used 10 J/cm2 (delivered twice [x2]) for all patients, followed by EGD with biopsies at 1, 3, 6, and 12 months. A second ablation procedure was performed if BE was present at 1 or 3 months. Patients received esomeprazole 40 mg twice a day for 1 month after ablation, and 40 mg every day thereafter. Postablation symptoms were quantified by using a 14-day symptom diary (scale, 0-100). A complete response (CR) was defined as all biopsy specimens negative for BE at 12 months.

SETTING

Eight U.S. centers, between September 2003 and September 2005.

PATIENTS

Patients were 18 to 75 years of age, with a diagnosis of BE (without dysplasia), with histopathology reconfirmation of the diagnosis within 6 months of enrollment.

RESULTS

In the dosimetry phase, 32 patients (29 men; mean age, 56.8 years) were enrolled. Median symptom scores returned to a score of 0 of 100 by day 3. There were no dose-related serious adverse events, and the outcomes at 1 and 3 months permitted the selection of 10 J/cm2 (x2) for the subsequent effectiveness phase of the study. In the effectiveness phase, 70 patients (52 men, 18 women; mean age, 55.7 years) were enrolled. Median symptom scores returned to a score of 0 of 100 by day 4. At 12 months (n = 69; mean, 1.5 sessions), a CR for BE was achieved in 70% of patients. There were no strictures and no buried glandular mucosa in either study phase (4306 biopsy fragments evaluated).

CONCLUSIONS

Circumferential ablation of nondysplastic BE by using this balloon-based ablation device can be performed with no subsequent strictures or buried glands and with complete elimination of BE in 70% of patients at 1-year follow-up.

Predictors of stricture formation after photodynamic therapy for high-grade dysplasia in Barrett's esophagus

BACKGROUND

Stricture formation is the leading cause of long-term morbidity after photodynamic therapy (PDT). Risk factors for stricture formation have not been studied.

OBJECTIVE

To assess risk factors for stricture formation in patients undergoing PDT for Barrett's esophagus with high-grade dysplasia (HGD).

DESIGN

Retrospective cohort study.

SETTING

Barrett's Unit, Mayo Clinic, Rochester, Minnesota.

METHODS

Records of patients undergoing PDT for HGD were reviewed. Patients underwent PDT by using either bare cylindrical diffusing fibers (2.5-5.0 cm in length) or balloon diffusers with 5- to 7-cm windows. Univariate and multivariate logistic regression analyses were performed to assess risk factors for stricture formation.

MAIN OUTCOME MEASUREMENT

Esophageal stricture formation.

RESULTS

Thirty-five of 131 patients (27%) developed strictures. On multivariate analysis, statistically significant predictors of stricture formation were the following: EMR before PDT was odds ratio (OR) 2.7, 95% confidence interval (CI) 1.13-6.59; a prior history of esophageal stricture was OR 2.7, 95% CI 1.15-6.47; and the number of PDT applications was OR 2.2, 95% CI 1.22-4.12. The OR for stricture formation in patients when centering balloons were used was 0.41, 95% CI 0.11-1.46, P = .168, indicating that centering balloons did not significantly decrease the risk of stricture formation.

LIMITATIONS

Retrospective single-center study; small proportion of patients treated with centering balloons.

CONCLUSIONS

Risk factors for development of strictures after PDT included history of a prior esophageal stricture, performance of EMR before PDT, and more than 1 PDT application in 1 treatment session. The use of centering balloons was not associated with a statistically significant reduction in the risk of stricture formation.

Preoperative diagnosis of extrapancreatic neural invasion in pancreatic cancer

BACKGROUND & AIMS

Pancreatic cancer recurs in most patients after resection with curative intent. Recurrence is particularly common in patients with extrapancreatic neural invasion (EPNI), the presence of which correlates with poor prognosis. Macroscopic EPNI may be detected with conventional noninvasive imaging and endoscopic ultrasound (EUS) imaging, but microscopic EPNI has required postoperative pathologic examination of surgical specimens. We report the preoperative diagnosis of cancer infiltration into celiac ganglia. We hypothesized that microscopic pancreatic cancer metastasis to neural ganglia can be detected by EUS-guided biopsy examination.

METHODS

We performed a retrospective review of patients with pancreatic cancer undergoing EUS in whom celiac ganglia were sampled to exclude malignant infiltration.

RESULTS

Six patients with pancreatic cancer underwent EUS-guided fine-needle aspiration or trucut biopsy examination of presumed celiac ganglia. Metastatic cancer was found in ganglia of 2 patients. Specimen review identified adenocarcinoma and neural tissue in the absence of lymphocytes. At laparoscopy, 1 of the 2 patients with positive celiac biopsy specimens also had several unexpected peritoneal metastatic deposits. The other patient was considered to have locally advanced unresectable disease. Both patients are receiving supportive care.

CONCLUSIONS

EPNI may be shown preoperatively in patients with pancreatic cancer using EUS-guided sampling of celiac ganglia. A preoperative diagnosis of EPNI has the potential to improve staging accuracy and patient outcomes.

Phase I trial of oral MAC-321 in subjects with advanced malignant solid tumors

PURPOSE

MAC-321 is a novel taxane that has demonstrated exceptional activity in human xenograft models when administered intravenously and orally. Preclinical studies of MAC-321 have shown antitumor activity in MDR-expressing and paclitaxel-resistant tumors. This phase I dose escalation study was performed to determine the safety, tolerability, and pharmacokinetic profile of orally administered MAC-321 given once every 21 days. Preliminary antitumor activity of MAC-321 was also examined.

METHODS

Key eligibility criteria included adult subjects with refractory solid tumors or solid tumors for which conventional therapy was unsuitable or did not exist, good performance status (ECOG ( 2), and adequate hematologic, hepatic, and renal functions. Plasma pharmacokinetic (PK) sampling was performed during the first cycle of therapy.

RESULTS

Five dose levels of MAC-321 ranging from 25 to 75 mg/m(2) were evaluated in 18 subjects (four women and 14 men). MAC-321 was well tolerated at the first three dose levels (25, 37, 50 mg/m(2)). Two subjects developed dose-limiting toxicities (DLTs) at 75 mg/m(2); one subject with grade 3 and one subject with grade 4 neutropenia with fever. Three subjects treated at an intermediate dose level of 60 mg/m(2) had no DLTs. However, the study was terminated prior to completion of the maximal tolerated dose cohort after subjects treated with intravenous MAC-321 in a concurrent study experienced life-threatening toxicities. Other common toxicities included grades 1-2 fatigue and grades 1-2 diarrhea. There was substantial interpatient variability in the PK parameters. MAC-321 was rapidly absorbed with a mean C (max) value of less than 1 h. Mean C (max) and AUC values generally increased in a dose-related manner. The median terminal phase elimination half-life was 45 h (range 20-228 h). Disease stabilization was seen in four subjects with the following tumors: mesothelioma (14 cycles), chondrosarcoma (12 cycles), small cell carcinoma (10 cycles), and prostate carcinoma (6 cycles).

CONCLUSIONS

MAC-321 can be safely administered orally once every 21 days up to a dose of 60 mg/m(2). The major DLT was neutropenic fever. Four subjects had disease stabilization.

Impact of endoscopist withdrawal speed on polyp yield: implications for optimal colonoscopy withdrawal time

BACKGROUND

In 2002, a U.S. Multi-Society Task Force on Colorectal Cancer recommended that the withdrawal phase for colonoscopy should average at least 6-10 min. This was based on 10 consecutive colonoscopies by two endoscopists with different adenoma miss rates.

AIMS

To characterize the relationship between endoscopist withdrawal time and polyp detection at colonoscopy, and to determine the withdrawal time that corresponds to the median polyp detection rate.

DESIGN

Procedural data from out-patient colonoscopies performed at the Mayo Clinic, Rochester during 2003 were reviewed. Endoscopists were characterized by their mean withdrawal time for a negative procedure and individual polyp detection rate.

RESULTS

A total of 10 955 colonoscopies performed by 43 endoscopists were analysed. Median withdrawal time was 6.3 min (range: 4.2-11.9); polyp detection rate was 44.0% (all polyps), 29.8% (< or = 5 mm), 5.9% (6-9 mm), 6.7% (10-19 mm), 2.1% (> or = 20 mm). Longer withdrawal time was associated with higher polyp detection rate (r = 0.76; P < 0.0001); this relationship weakened for larger polyps (r = 0.19 for polyps 6-9 mm, r = 0.28 for polyps 10-19 mm, r = 0.02 for polyps > or = 20 mm). Overall median polyp detection rate corresponded to a withdrawal time of 6.7 min.

CONCLUSION

Our findings support a colonoscopy withdrawal time of at least 7 min, which correlates with higher colon polyp detection rates.

Progress in chemoprevention drug development: the promise of molecular biomarkers for prevention of intraepithelial neoplasia and cancer--a plan to move forward

This article reviews progress in chemopreventive drug development, especially data and concepts that are new since the 2002 AACR report on treatment and prevention of intraepithelial neoplasia. Molecular biomarker expressions involved in mechanisms of carcinogenesis and genetic progression models of intraepithelial neoplasia are discussed and analyzed for how they can inform mechanism-based, molecularly targeted drug development as well as risk stratification, cohort selection, and end-point selection for clinical trials. We outline the concept of augmenting the risk, mechanistic, and disease data from histopathologic intraepithelial neoplasia assessments with molecular biomarker data. Updates of work in 10 clinical target organ sites include new data on molecular progression, significant completed trials, new agents of interest, and promising directions for future clinical studies. This overview concludes with strategies for accelerating chemopreventive drug development, such as integrating the best science into chemopreventive strategies and regulatory policy, providing incentives for industry to accelerate preventive drugs, fostering multisector cooperation in sharing clinical samples and data, and creating public-private partnerships to foster new regulatory policies and public education.

The development of a fluorescence in situ hybridization assay for the detection of dysplasia and adenocarcinoma in Barrett's esophagus

The goal of this study was to identify a set of fluorescence in situ hybridization probes for the detection of dysplasia and adenocarcinoma in patients with Barrett's esophagus. We examined 170 brushing specimens from 138 patients with Barrett's esophagus or a history of Barrett's esophagus using fluorescence in situ hybridization with probes to 5p15, 5q21-22, centromere 7, 7p12, 8q24.12-13, centromere 9, 9p21, centromere 17, 17p13.1, 17q11.2-12, 20q13.2, and centromere Y. Receiver-operator curves were used to determine the sensitivity and specificity of various four-probe combinations for detecting low-grade dysplasia, high-grade dysplasia, and esophageal adenocarcinoma. Endoscopic biopsy results were used as the gold standard. Numerous four-probe combinations provided a similarly high sensitivity and specificity. Of these, a set consisting of probes to 8q24, 9p21, 17q11.2, and 20q13.2 was found to have a sensitivity and specificity, respectively, of 70% and 89% for low-grade dysplasia, 84% and 93% for high-grade dysplasia, and 94% and 93% for esophageal adenocarcinoma. This probe set was chosen for future prospective clinical evaluations based on its high sensitivity and specificity, its ability to distinguish adenocarcinoma and high-grade or low-grade dysplasia from lesser diagnostic categories, and the favorable signal quality for each of the probes.

Frozen section analysis of esophageal endoscopic mucosal resection specimens in the real-time management of Barrett's esophagus

BACKGROUND & AIMS

The aim of this study was to assess the validity of frozen section analysis of endoscopic mucosal resection (EMR) specimens from Barrett's esophagus as compared with permanent sections for the detection of neoplasia. Frozen sections help to give immediate feedback for surgical procedures. It has not been determined whether EMR can be adequately interpreted by using frozen sections to aid endoscopists in completely resecting neoplastic lesions.

METHODS

EMR specimens from Barrett's esophagus with high-grade dysplasia (HGD) and/or carcinoma were tested by frozen section. Pathologists evaluated EMR specimens for the depth of invasion as well as the appearance of clear margins of resection. The kappa statistic was calculated to assess the degree of agreement between the frozen section and permanent section diagnoses.

RESULTS

Twenty-three consecutive patients underwent 30 EMRs with frozen section diagnosis. Frozen section revealed a carcinoma in 7 specimens (23%) and dysplasia in 20 (66%). Permanent sections found carcinoma in 8 specimens (26%), dysplasia in 19 specimens (63%), and normal or nondysplastic Barrett's esophagus in the remainder. The kappa statistic for the depth of invasion of EMR specimens was 0.93 (near perfect agreement). The kappa statistic for the margins of the EMR specimens was 0.80 (excellent agreement).

CONCLUSIONS

This study indicated that frozen section analysis of esophageal EMR specimens is valid as compared with permanent section. This technique might allow rapid evaluation about the degree and depth of involvement of cancers. This allows physicians to make decisions regarding further therapy if margins are involved or decrease the use of EMR for histologically benign-appearing lesions.

Mechanisms of disease: Carcinogenesis in Barrett's esophagus

The pathogenesis of cancer in Barrett's esophagus is multifactorial. Gastroesophageal reflux seems to be important in the initiation of Barrett's esophagus, but its role in promoting carcinogenesis has yet to be established. Diet, lifestyle and carcinogens, especially the nitrates, may be important in the development of carcinogenesis, and require further investigation. Inhibition of reflux-stimulated inflammatory changes, for example by inhibiting cyclooxygenase, holds promise for decreasing cancer progression. Similarly, dietary and lifestyle modification used in the management of reflux may also help to prevent the development of esophageal cancer. The molecular changes that are associated with the development of cancer in Barrett's esophagus offer several potential areas of intervention to prevent and manage esophageal cancer. Limiting cell growth, increasing apoptosis of damaged cells, limiting cell invasion and angiogenesis factors could be useful to accomplish this goal. Having a greater understanding of the pathogenesis of this condition can only help to develop more management options in the future.

Current Strategies in the management of Barrett's esophagus

Barrett's esophagus has become a very important topic in gastroenterology. Its management may vary from essentially a surveillance strategy to highly invasive esophagectomy. The variation in management strategies has occurred because of the current perceptions regarding cancer risks, which range from almost negligible to an incidence of 30% in high-grade dysplasia. Although it is clear that most patients with Barrett's esophagus without dysplasia will not require therapy, the prospect of continued surveillance is unpleasant at best. Promising future tools and techniques for surveillance and treatment are described in this review.

Endoscopic ultrasound-guided trucut biopsy of the cyst wall for diagnosing cystic pancreatic tumors

BACKGROUND & AIMS

Nonoperative methods for diagnosis of pancreas cysts often lack sufficient accuracy. Accurate diagnosis is needed to determine prognosis and guide clinical management. The aim of this study was to determine whether the tissue obtained by endoscopic ultrasound-guided trucut biopsy (EUS TCB) is sufficient for histologic diagnosis of cystic pancreatic tumors (CPTs).

METHODS

EUS TCB was performed in patients with a suspected CPT. A dedicated gastrointestinal pathologist reviewed the core biopsies. The final diagnosis was based on clinical, laboratory, imaging, and biopsy findings, and resected specimens when available.

RESULTS

EUS TCB was performed in 10 patients with a suspected CPT. Final diagnoses included serous cystadenoma (SCA, n=5), islet cell tumor (n=2), mixed seromucinous lesion (n=1), polycystic disease of the pancreas (n=1), and pseudocyst (n=1). EUS TCB was nondiagnostic in 3 of 10 patients. Among the other 7 patients, TCB diagnosed 4 SCAs, obviating the need for planned surgery in 3 patients. In the fourth patient with an SCA, the TCB result ruled out metastatic disease from locally recurrent lung cancer, allowing a narrowed radiation field. EUS TCB confirmed the need for surgery in 2 patients with an islet cell tumor. In 1 patient, EUS TCB findings were "partially" diagnostic, leading to previously unplanned surgery.

CONCLUSIONS

This report establishes the capability and safety of EUS TCB to collect sufficient tissue for diagnosing CPTs. The results might help guide clinical management.

A comparative analysis by SAGE of gene expression profiles of Barrett's esophagus, normal squamous esophagus, and gastric cardia

BACKGROUND & AIMS

The metaplastic process in which the normal squamous epithelium of the distal esophagus is replaced by columnar-lined epithelium, known as Barrett's esophagus (BE), is poorly understood. The aim of this study was to define, analyze, and compare transcription profiles of BE, normal cardia epithelium, and squamous epithelium to gain more insight into the process of metaplasia and to identify uniquely expressed genes in these epithelia.

METHODS

Serial analysis of gene expression was applied for obtaining transcription libraries of biopsy specimens taken from a BE-affected patient with intestinal type of metaplasia and from normal squamous and gastric cardia epithelia. Validation of results by reverse-transcription polymerase chain reaction and immunoblotting was performed using tissues of 20 patients with BE.

RESULTS

More than 120,000 tags were sequenced. Between BE and squamous 776, and between BE and gastric cardia 534 tags were significantly differentially expressed (P < .05, pairwise comparison). In contrast, squamous compared with gastric cardia epithelia showed significant differential expression of 1316 tags. The most up-regulated genes in BE compared with squamous epithelium were trefoil factors, annexin A10, and galectin-4. Each of the epithelia showed a unique cytokeratin expression profile.

CONCLUSIONS

This study provides a comparison of the transcriptomes of BE, squamous epithelium, and gastric cardia epithelium. BE proves to be an incompletely differentiated type of epithelium that shows similarities to both normal squamous and gastric cardia epithelia. In addition, several uniquely expressed genes are identified. These results are a major advancement in understanding the process of metaplasia that leads to BE.

Photodynamic therapy with porfimer sodium for ablation of high-grade dysplasia in Barrett's esophagus: international, partially blinded, randomized phase III trial

BACKGROUND

Barrett's esophagus (BE) may lead to high-grade dysplasia (HGD) and adenocarcinoma. The objective was to examine the impact of treating patients with BE and with HGD by using porfimer sodium (POR) and photodynamic therapy (PDT) for ablating HGD and reducing the incidence of esophageal adenocarcinoma.

METHODS

The design was a multicenter, partially blinded (pathology), randomized clinical trial conducted in patients with BE who have HGD. There were 30 contributing centers. A total of 485 patients were screened, with 208 in the intent-to-treat population and 202 in the safety population. Patients were randomized on a 2:1 basis to compare PDT with POR plus omeprazole (PORPDT) with omeprazole only (OM). The main outcome measurement was complete HGD ablation occurring at any time during the study period.

RESULTS

There was a significant difference (p < 0.0001) in favor of PORPDT (106/138 [77%]) compared with OM (27/70 [39%]) in complete ablation of HGD at any time during the study period. The occurrence of adenocarcinoma in the PORPDT group (13%) (n=18) was significantly lower (p < 0.006) compared with the OM group (28%) [corrected] (n=20). The safety profile showed 94% of patients in the PORPDT group and 13% of patients in the OM group had treatment-related adverse effects. The limitations of the study were that PDT therapy may have had to be applied more than once and that patients spent more time in treatment. The patients and the physicians were not blinded to the treatment.

CONCLUSIONS

PORPDT in conjunction with omeprazole is an effective therapy for ablating HGD in patients with BE and in reducing the incidence of esophageal adenocarcinoma.

Pilot study to assess patient outcomes following endoscopic application of photodynamic therapy for advanced cholangiocarcinoma

BACKGROUND

Photodynamic therapy (PDT) has demonstrated promise in the palliative treatment of advanced cholangiocarcinoma. The aim of this pilot study was to assess the outcome in patients with non-resectable cholangiocarcinoma following endoscopic application of PDT directly into the biliary tract.

METHODS

In patients with advanced cholangiocarcinoma, endoscopic retrograde cholangiopancreatography (ERCP) was performed to define the proximal and distal extent of intraductal tumor. Sodium porfimer was administered intravenously to all patients. Forty-eight hours later, a commercially available cylindrical diffusing laser fiber (1-2.5 cm in length, OptiGuide) designed for esophageal use was advanced across the biliary strictures. Laser light was applied at a power of 400 mW/cm fiber for a total energy of 180 J/cm(2) using an argon-pumped tunable dye laser. Patients received endoscopic PDT every 3 months provided they maintained a favorable performance status. Plastic biliary stents were replaced immediately following light application and were maintained in all patients.

RESULTS

Using a preloaded catheter, adequate positioning of the laser fiber was achieved in all patients. Eight patients with advanced cholangiocarcinoma received a total of 19 PDT treatments, range 1-5 treatments/patient. All eight patients were followed until death; mean follow-up was 9.8 months. Median survival from the date of the first PDT treatment was 276 days, which compares favorably with published series that have reported median survival times between 45 and 127 days for patients with bismuth type III and IV tumors treated with stenting alone.

CONCLUSIONS

Endoscopic application of PDT demonstrates promise in prolonging survival in patients with advanced cholangiocarcinoma. Additional randomized clinical trials using commercially available fibers are needed to fully evaluate both the optimum frequency and treatment interval of endoscopic PDT in the management of advanced cholangiocarcinoma.

Age-related changes in the pancreas identified by EUS: a prospective evaluation

BACKGROUND

EUS is an important modality for the diagnosis of pancreatic disease. An understanding of normal pancreatic ductal and parenchymal variation in asymptomatic individuals is essential to improve EUS accuracy. The primary aim of this study was to determine age-related pancreatic parenchymal and ductular changes identifiable on EUS in individuals with no history or symptoms of pancreaticobiliary disease. Secondary aims were to define demographic and clinical factors associated with identifiable pancreatic parenchymal and ductular changes, and to determine the main pancreatic-duct diameter and pancreatic-gland width according to age.

METHODS

Patients referred for either upper endoscopy or EUS for an indication unrelated to pancreaticobiliary disease were prospectively enrolled. Patients were stratified by age (<40, 40-60, >60 years). Each patient was assessed for the presence of EUS findings for chronic pancreatitis. Logistic regression was used to identify factors associated with an abnormality.

RESULTS

A total of 120 patients (63 men, 57 women; median age, 52 years, interquartile range [IQR] 40-61 years) were prospectively evaluated. At least one parenchymal and/or ductular abnormality was identified in 28% of the patients, with a trend of increasing abnormality with age: <40 years (23%), 40 to 60 years (25%), and >60 years (39%); p = 0.13. No patient had more than 3 abnormal EUS features. Hyperechoic stranding (n = 22) was the most common finding in all age groups. The odds for any abnormality in men (relative to women) was significantly higher (OR 2.9: 95% CI[1.2, 6.8], p = 0.01), with 38% of men and 18% of women having an abnormality. Smoking, low alcohol intake, body mass index, and endoscopic finding were not significantly associated with an abnormal EUS. The overall median pancreatic-gland width and main pancreatic duct diameter were 15 mm (IQR 6-25 mm) and 1.7 mm (IQR 0.9-4.3 mm), respectively.

CONCLUSIONS

The frequency of EUS abnormalities in patients without clinical evidence of chronic pancreatitis increases with age, particularly after 60 years of age. The threshold number of EUS criteria for the diagnosis of chronic pancreatitis is variable. However, the typically used standard of 3 or more criteria appears appropriate. A higher number of threshold criteria may be needed in males and to a lesser extent in patients over 40 years of age, which should be related to clinical history and other structural or functional studies. Ductal or parenchymal calculi, ductal narrowing, ductal dilatation, or more than 3 abnormalities appear to be more specific features for the EUS diagnosis of chronic pancreatitis at any age.

Endoscopic Mucosal Resection: Esophageal Applications

Endoscopic mucosal resection is an invaluable tool to diagnose and potentially treat superficial cancers in Barrett's esophagus as well as squamous cell cancers. The technique can be performed using equipment available in most endoscopic laboratories. The tissue retrieved from these procedures gives the endoscopist histologic information regarding tumor depth of penetration, which is critical to treatment of early cancers. In addition, standard pinch biopsies are often unable to diagnose malignancies that may underlie areas of dysplasia or even normal mucosa. Endoscopic mucosal resection can be used to diagnose these lesions with relative safety, particularly when applied to the esophagus.

Knowledge of indications for EUS among gastroenterologists and non-gastroenterologists

BACKGROUND

The level of awareness among non-gastroenterologists of the indications for EUS is unknown. This study assessed knowledge of the indications and the utility of EUS among gastroenterologists and non-gastroenterologists in a large multispecialty academic practice.

METHODS

A questionnaire was designed that tested knowledge of the indications for EUS with respect to 4 organ systems: esophagus, gastroduodenum, hepatopancreatobiliary system and colorectum. The questionnaire was distributed by electronic mail to gastroenterologists, general internists, non-gastroenterologist subspecialists, and surgeons in a large multispecialty practice.

RESULTS

The survey was distributed to 659 attending physicians of whom 227 (34%) replied: gastroenterologists (53%), internists (30%), non-gastroenterologist specialists (33%), and surgeons (28%). Knowledge of appropriate indications was highest among gastroenterologists (84.3%) compared with internists (68.9%), non-gastroenterologist specialists (65.4%), and surgeons (65.3%) (p < 0.0001). Among all non-gastroenterologists, knowledge of indications for hepatopancreatobiliary (mean 66.3% correct responses) and colorectal applications (64.0%) was inferior to knowledge of esophageal (71.5%) and gastroduodenal (83.5%) applications.

CONCLUSIONS

Internists, non-gastroenterologist specialists, and surgeons in a large multispeciality practice have moderate knowledge of the indications and the utility of EUS. Knowledge was at the lowest level for hepatopancreatobiliary and colorectal applications of EUS for all 3 groups of non-gastroenterologists. Future studies should focus on the education of non-gastroenterologists regarding the role of EUS and assess the impact of such education on the appropriateness of EUS referral patterns.

Detection and staging of esophageal cancers

PURPOSE OF REVIEW

Technology for detection and staging of esophageal cancer has made significant strides advances in the past 2 years. These advances have led to the enhanced selection of appropriate treatments for esophageal cancer. Cancers that are discovered at an early stage can be treated with endoscopic therapy, whereas advanced cancers are primarily treated with chemotherapy and radiation.

RECENT FINDINGS

Detection of esophageal cancer can be enhanced by two major mechanisms: one is by enhancing the lesion, which has typically been done using vital dyes and the other is by changing the method of imaging of the lesion, which has been accomplished by the use of several technologies including fluorescence and optical coherence tomography. Neither of these techniques has been proven, but some investigators have been able to use them to enhance cancer detection. Similar technologies have been applied to staging esophageal cancer. The optical imaging devices also have the potential to stage mucosa-based malignancy. The use of positron emission tomography has been the most recent development that may have application for advanced cancer. Endoscopic ultrasonography has also been improved in resolution and ability to perform fine needle aspiration. The most significant development for staging early cancers is mucosal resection. Finally, by using mucosal resection techniques, the depth of tumor invasion can be established by histology, which allows gastroenterologists to treat early cancers with greater confidence regarding rates of metastatic disease.

SUMMARY

Early detection of esophageal cancer can be enhanced by the use of vital dyes for mucosal staining, but the advancement of novel optical diagnostic strategies may be more suitable for clinical use. The primary advantage of these new staging methods is to clearly identify early stage cancer that potentially can be treated without traditional surgical resection techniques. More advanced cancers can be staged with positron emission tomography, but definitive studies demonstrating its role are still lacking.

Optical detection and eradication of dysplastic Barrett's esophagus

Dysplastic Barrett's esophagus is a condition that offers multiple diagnostic and therapeutic challenges. The diagnosis of dysplasia within Barrett's esophagus currently relies on periodic endoscopic surveillance with multiple biopsies, a methodology limited by random sampling error, inconsistent histopathologic interpretation and delay in diagnosis. Optical spectroscopic and imaging techniques have the potential to identify dysplastic or early neoplastic lesions in real-time. These diagnostic modalities are needed to enhance the endoscopic surveillance of Barrett's esophagus in the future as well as help to define lesions for endoscopic therapy. Esophagectomy has been the standard of care for Barrett's esophagus with high-grade dysplasia although it is a procedure associated with significant morbidity and mortality. Minimally invasive endoscopic ablative therapies are attractive and less morbid alternatives to esophagectomy, with promising results obtained from the use of light-activated drugs (i.e., photodynamic therapy). The combination of novel optical diagnostic techniques and therapies will provide the endoscopist with much needed tools that can considerably enhance the management of patients with Barrett's esophagus. This article reviews the current status and future prospects of optical-based modalities for diagnosis and therapy of dysplastic Barrett's esophagus.

Photodynamic therapy in Barrett's esophagus

Photodynamic therapy (PDT) was one of the earliest ablative techniques applied to Barrett's esophagus. The rationale for this use was the ability to treat large amounts of esophageal mucosa in a single rapid application. Additionally, PDT has the ability to treat early carcinoma and dysplastic tissue. Because a small carcinoma in dysplastic Barrett's esophagus cannot not be excluded, PDT therapy is a reasonable treatment in this setting. The treatment involves the use of a light and drug combination that must be administered with close attention to dosimetry, since tissue effects of the therapy are delayed and cannot be observed at the time of treatment. Drug administration of sodium porfimer should precede photoradiation by 48 hours. Overall results with this treatment have been good. Case series have established a success rate of 88% to 100% in elimination of high-grade dysplasia. The only randomized multi-center prospective trial in the treatment of Barrett's esophagus with high-grade dysplasia has established that the treatment eliminates high-grade dysplasia better than administration of proton pump inhibitors alone. Unfortunately, there are significant adverse events, including cutaneous photosensitivity, odynophagia, stricture formation, and lack of response.

Combined endoscopic mucosal resection and photodynamic therapy versus esophagectomy for management of early adenocarcinoma in Barrett's esophagus

BACKGROUND & AIMS

Although esophagectomy is the standard of care for treating early adenocarcinoma in Barrett's esophagus, the procedure is associated with significant morbidity and mortality. For these patients, the multimodal approach of endoscopic mucosal resection and photodynamic therapy (EMR/PDT) may be a viable, less invasive option.

METHODS

A retrospective review (1996-2001) of all patients undergoing either combined EMR/PDT group or esophagectomy (SURG) for early-stage Barrett's adenocarcinoma was performed. Data were collected on patient demographics, tumor staging, procedure-related morbidity and mortality, persistence or recurrence of cancer, and cancer-related deaths after therapy. Differences in outcomes between the 2 groups were assessed.

RESULTS

Twenty-four patients were identified in the EMR/PDT group and 64 in the SURG group. The SURG group was found to have a significantly higher procedure-related complication rate compared with the EMR/PDT group (31 vs. 4; P < 0.01). There were no procedure-related deaths in the EMR/PDT group, whereas one death occurred in the SURG group as a result of complications. Eighty-three percent of patients (20 of 24) in the EMR/PDT group and all patients in the SURG group remained free of cancer over a follow-up of 12 +/- 2 and 19 +/- 3 months, respectively. Four patients in the EMR/PDT group failed to respond to therapy; 2 of them underwent alternate therapies and are free of disease, whereas the other 2 died of unrelated causes.

CONCLUSIONS

The combination of EMR/PDT seems to be a viable and less morbid alternative to standard esophagectomy in patients presenting with early Barrett's esophageal adenocarcinoma. A prospective randomized, controlled trial of EMR/PDT compared with esophagectomy for managing early adenocarcinoma in Barrett's esophagus may be warranted.

Management of Barrett's esophagus with high-grade dysplasia

About 38% to 73% of patients diagnosed with BE with HGD and who went on to have an esophagectomy already had esophageal ACA. The low 5-year survival rate of invasive esophageal ACA places pressure on the physician to find a way to prevent or to remove the cancer. Endoscopic ablative therapies have been developed, but these new technologies are to be considered as a secondary option. Although there are many recent improvements in surveillance strategies and endoscopic ablative therapies, series are small and follow-up is short. These modalities do show promise and may be a good option in the future for patients who are poor surgical candidates. At the present time, the standard of care for BE with HGD in good surgical candidates is still esophagectomy.

Isolation and sequencing of a novel tropomyosin isoform preferentially associated with colon cancer

BACKGROUND & AIMS

Nonmuscle human tropomyosin (hTM) isoforms have distinct functions and may play important roles in various disease processes.

METHODS

In an attempt to identify colon epithelial tropomyosin isoform, a complementary DNA library prepared from a human colon cancer cell line T84 was screened by an oligonucleotide probe complementary to messages of all known hTM isoforms. A novel clone called TC22 was obtained. The amino acid sequence of TC22 isoform is identical to isoform 5 (hTM5) apart from the C terminal domain, amino acids 222-247 coding the exon 9.

RESULTS

Northern blot analysis showed that TC22 message is expressed in transformed epithelial cell lines and tumor tissues but not in normal epithelial cells. We developed a monoclonal antibody specific to TC22 isoform (TC22-4). By Western blot and immunoperoxidase assays, we analyzed 105 colonic specimens (fresh frozen and formalin fixed) from 96 patients with colon polyps (hyperplastic) or adenomas with or without dysplasia and cancer. Twenty-one of 22 (95%) of colon cancer specimens showed the presence of TC22, compared with only 1 of the 17 normal colon specimens and none of the 13 hyperplastic polyps (P < 0.0001). As assayed by immunoperoxidase staining, TC22 expression progressively increased in benign adenomatous polyps (35%) and polyps with mild and severe dysplasia (57% and 100%, respectively).

CONCLUSIONS

We cloned and sequenced a novel hTM isoform, TC22, which is strongly associated with colonic neoplasia and carcinoma. TC22 may provide a useful biomarker for surveillance of colon cancer.

Chemoprevention of esophageal adenocarcinoma by COX-2 inhibitors in an animal model of Barrett's esophagus

BACKGROUND & AIMS

Carcinogenesis in Barrett's esophagus (BE) is associated with an increased expression of cyclooxygenase (COX) 2. However, there has been no direct evidence that inhibition of COX-2 prevents cancer in BE. We studied the effect of MF-Tricyclic, a selective COX-2 inhibitor, on the development of BE and adenocarcinoma in a rat model.

METHODS

Four weeks after esophagojejunostomy, 105 Sprague-Dawley rats were randomized to a chow containing MF-Tricyclic or Sulindac, or a placebo. Ninety-six (92%) rats completed the study and were sacrificed at 28 +/- 2 weeks. The animals were assessed for the presence of cancer, tumor volume, BE, degree of inflammation, and COX-2 expression and activity.

RESULTS

MF-Tricyclic and Sulindac reduced the relative risk of development of esophageal cancer by 55% (95% confidence interval [CI] = 43%-66%, P < 0.008) and by 79% (95% CI = 68%-87%, P < 0.001), respectively, compared with controls. No significant differences were noted in the risk of esophageal cancer between the MF-Tricyclic and the Sulindac group (P = 0.34). The median tumor volume was not significantly different among the 3 groups (P = 0.081). Moderate to severe degree of inflammation was significantly more common (P = 0.005) in the control compared with the MF-Tricyclic and the Sulindac group; however, the prevalence of BE was not significantly different between groups (P = 0.98). Rats in the control group had higher tissue PGE2 level compared with the MF-Tricyclic and Sulindac groups (P = 0.038).

CONCLUSIONS

Selective and nonselective COX-2 inhibitors can inhibit inflammation, COX-2 activity, and development of adenocarcinoma induced by reflux. This provides direct evidence that COX-2 inhibitors may have chemopreventive potential in BE.

Nonsurgical management of Barrett's esophagus with high-grade dysplasia

Endoscopic management options for BE with high-grade dysplasia consist of either surveillance methods or endoscopic mucosal ablative therapies. Intensive surveillance once a person is diagnosed with high-grade dysplasia may avoid an unneeded esophagectomy because it appears that most patients with high-grade dysplasia may not progress to esophageal adenocarcinoma. Only a single study has been presented that demonstrates that this approach does not lead to missed opportunities for intervention before progression to advanced stage disease [20]. This study excluded patients with cancer detected within 1 year of diagnosis of high-grade dysplasia; thus, patients who wish to proceed with an observation approach should be aware that the rate of missed esophageal adenocarcinomas ranges from 38% to 73%. The ability to observe a patient with high-grade dysplasia, however, does have appeal because a number of these patients appear to lose the high-grade dysplasia over time. The other endoscopic management option for Barrett's esophagus with high-grade dysplasia is endoscopic mucosal ablative therapies. These include the KTP:YAG laser, the Nd:YAG laser, photodynamic therapy, and endoscopic mucosal resection. All ablative therapies are used in combination with control of gastroesophageal reflux. This allows the esophageal tissue to heal in an environment that is conducive to squamous mucosa. Although most are relatively small series with short durations of observation, they all have shown some promise in treating BE with high-grade dysplasia. These approaches have the advantage of eliminating the problem. The patient who is being observed must live with the thought of developing cancer. Patients who undergo successful ablation are returned to a normal life. The combination of therapies such as EMR with PDT may be the most promising approach to BE with high-grade dysplasia; however, the long-term effects of ablative therapy are not known and continued surveillance is still advised for this group of patients. The choice of a nonsurgical approach for the management of BE with high-grade dysplasia is ultimately up to the individual patient. All patients must be carefully informed of the treatment effects, possible outcomes, and the surgical alternative. Most patients who select nonsurgical approaches are either elderly or are not good surgical candidates. The choice is often affected by local expertise, as surgical procedures should be performed in centers with surgeons expert in esophagectomy. Nonsurgical approaches should also be performed by physicians who are familiar with their application. Future advances in nonsurgical techniques such as new photosensitizers in PDT and improvements in diagnostic techniques may allow patients a greater opportunity to preserve their esophagus.

The effect of selective cyclooxygenase-2 inhibition in Barrett's esophagus epithelium: an in vitro study

BACKGROUND

Individuals with Barrett's esophagus, in which the normal squamous esophageal epithelium is replaced with a columnar mucosa, are at increased risk for esophageal adenocarcinoma. Mucosal injury may be involved in the progression to neoplasia via the synthesis of prostaglandins and other mediators of inflammation. Cyclooxygenase (COX)-2 is the rate-limiting enzyme involved in prostaglandin synthesis. We examined the effect of inhibiting COX-2 activity in Barrett's esophageal cells.

METHODS

Primary esophageal epithelial and fibroblast cell cultures were established from endoscopic biopsy specimens from 20 consecutive patients with Barrett's esophagus. COX-2 expression and activity were determined on pooled cell cultures by reverse transcription-polymerase chain reaction and prostaglandin E(2) (PGE(2)) enzyme immunoassay, respectively. Proliferation was measured by Ki-67 staining. PGE(2) levels were determined in supernatants from epithelial cells treated with the selective COX-2 inhibitor NS-398, proinflammatory cytokines (interleukin 1beta and tumor necrosis factor-alpha), and conditioned medium from fibroblast cultures (both unstimulated and stimulated with proinflammatory cytokines).

RESULTS

Esophageal epithelial cells and fibroblasts expressed COX-2 messenger RNA. Compared with control-treated cells, NS-398 decreased proliferation of Barrett's esophageal epithelial cells by 55% (95% confidence interval = 47.1% to 63.8%; P<.001) and decreased COX-2 activity. The addition of exogenous PGE(2) reversed the antiproliferative effect of NS-398 on Barrett's esophageal epithelial cells. Proinflammatory cytokines did not affect COX-2 activity in esophageal epithelial cells but stimulated COX-2 activity in fibroblasts. However, conditioned medium from unstimulated and stimulated fibroblasts increased COX-2 activity in esophageal epithelial cells.

CONCLUSION

COX-2 is functionally active in Barrett's esophagus because treatment with the COX-2 inhibitor hinders proliferation of Barrett's esophageal epithelial cells in culture, but proliferation is restored by treatment with prostaglandin. These results raise the possibility that inhibition of COX-2 may have chemopreventive potential for Barrett's esophagus.

Allelic imbalance of 7q32.3-q36.1 during tumorigenesis in Barrett's esophagus

Malignant transformation of Barrett's esophagus is characterized by three distinct premalignant stages: intestinal metaplasia (MET), low- (LGD), and high-grade dysplasia (HGD). We reported recently an increase in the frequency of loss of 7q33-q35 between LGD and HGD as determined by comparative genomic hybridization (P. H. J. Riegman et al., Cancer Res., 61: 3164-3170, 2001). Now the 7q32.3-q36.1 region was additionally characterized by allelotype analysis with 11 polymorphic markers in 15 METs, 20 LGDs, 20 HGDs, and 20 Barrett's adenocarcinomas from different patients. Low percentages of imbalance were determined in METs and LGDs, 7% and 10%, respectively, whereas HGDs and Barrett's adenocarcinomas revealed high percentages of loss, 75% and 65%, respectively. This difference in frequency between LGDs and HGDs appeared highly significant: P = 0.00007. The majority of imbalances were found at D7S2439 and D7S483, located on 7q36.1. These data suggest that markers from this area can be used as a diagnostic tool in Barrett's esophagus, i.e., to distinguish between watchful waiting and active treatment.

Role of mucosal ablative therapy in the treatment of the columnar-lined esophagus

With the high prevalence of gastroesophageal reflux-like symptoms in the United States and the association between GERD symptoms and the premalignant condition of BE, there is more and more demand for new and efficacious techniques to treat BE. A wide variety of endoscopic mucosal ablative techniques have been developed with promising initial results. Long-term control of neoplastic risk, however, has not been demonstrated, and most studies demonstrate that there is still potentially some intestinal mucosa present underneath squamous mucosa. Currently, more study is needed to determine which patient groups require therapy of any kind and to determine which therapies would be the most efficacious. Genetic markers may aid in identification of subgroups that are at risk for cancer and help to identify those who would respond to mucosal therapy. Even in patients who have HGD, subgroups of patients who have focal HGD have been found to have better prognosis than those who have more widespread HGD. Currently, there is sufficient information to consider mucosal ablative techniques in patients who are not good surgical candidates. Photodynamic therapy, APC, KTP, Nd:YAG and argon lasers, MPEC, and EMR may provide good alternatives, depending on the degree of dysplasia, the extent of disease, and the age of the patient. Photodynamic therapy and Nd:YAG laser therapy have been applied to more neoplastic lesions, whereas KTP:YAG, APC, and multipolar coagulation have been successful in nondysplastic Barrett's mucosa. In the future, there will be more information to justify the application of mucosal ablative therapy in selected patients.

Inhibition of p38 kinase mimics survival signal-linked protection against apoptosis in rat cerebellar granule neurons

The mitogen-activated protein kinase (MAPK) cascades are thought to be important mediators in the transduction of extracellular signals into cellular responses. The p38 kinase, a member of the MAPK superfamily, is activated by a wide variety of extracellular stimuli and has been implicated in neuronal apoptosis induced by glutamate. In this study we have examined the role of p38 kinase in the potassium deprivation model of apoptosis in rat cerebellar granule neurons (CGN). An increase in p38 kinase activity was observed with a 15-minute potassium deprivation when compared to the basal level. We also found that SB203580 and PD169316, specific p38 kinase inhibitors, significantly attenuated apoptosis in potassium-deprived cells in a dose dependent manner. A decrease in caspase-3 mediated DEVD-MCA, substrate hydrolysis and the appearance of the 120 kDa-spectrin breakdown product in cells treated with SB203580 further suggests that the p38 kinase acts upstream of caspase-3 in the apoptosis cascade. The data provides evidence for an essential role of p38 kinase in mediating apoptotic cell death in CGN and the inhibition of p38 kinase mimics the suppression of apoptosis provided by natural survival signals.

Combined endoscopic mucosal resection and photodynamic therapy for esophageal neoplasia within Barrett's esophagus

BACKGROUND

Endoscopic mucosal resection (EMR) and photodynamic therapy have been proposed as treatments for early stage cancers. EMR is limited by its focal nature whereas photodynamic therapy is dependent on precise staging. The combination of EMR and photodynamic therapy were studied in the treatment of superficial cancer in patients with Barrett's esophagus.

METHODS

Seventeen consecutive nonsurgical patients with superficial cancers underwent EMR followed by photodynamic therapy with a porphyrin photosensitizer. Photoradiation was performed at 630 nm for a total dose of 200 J/cm of diffuser.

RESULTS

Seventeen patients (15 men; mean age 69 +/- 13 years) underwent EMR. The mean diameter of mucosal resection was 1 cm. The margins were involved by cancer in 3 cases. EMR improved staging in 8 patients (47%). Sixteen (94%) patients remained in remission (median follow-up 13 months). Complications included minor bleeding after EMR in 1 patient (6%), stricture in 5 (30%), cutaneous phototoxicity in 2 (12%), and supraventricular tachycardia in 1 patient (6%).

CONCLUSIONS

Combined EMR and photodynamic therapy appears to be an effective and safe therapy for superficial esophageal cancer within Barrett's esophagus. This combination improves cancer staging, removes the superficial cancer, and eliminates remaining mucosa at risk for cancer development.

Novel synthesis of 4,5-diarylphenanthrenes via C2-C6 cyclization of benzannulated enyne-allenes

A new synthetic pathway to the 4,5-diarylphenanthrenes 8 having a helical twist in their structures was developed. The synthetic sequence involves condensation of the diketone 5 with 2 equiv of the lithium acetylides derived from the diacetylenes 4 followed by protonation to produce the propargylic alcohols 6. Reduction of 6 with triethylsilane in the presence of trifluoroacetic acid furnished the tetraacetylenic hydrocarbons 7 in nearly quantitative yields. Treatment of 7 with potassium tert-butoxide under refluxing toluene at 110 degrees C for up to 10 h then furnished the 4,5-diarylphenanthrenes 8. Apparently, the transformation from 7 to 8 involves initial prototropic isomerizations to form the benzannulated enyne-allenes 9. Two subsequent formal intramolecular Diels-Alder reactions via the biradicals 10 and 12 derived from the C(2)-C(6) cyclizations then led to 13, which in turn underwent tautomerizations to give 8. The structure of 8a was established by the X-ray structure analysis, showing that the two phenyl substituents are bent away from each other and the central aromatic system is severely distorted with a helical twist. The existence of a helical twist in 8 imposed by the aryl groups at the 4- and 5-positions was also revealed with a set of AB (1)H NMR signals for the diastereotopic methylene hydrogens on the five-membered rings.

The novel calpain inhibitor SJA6017 improves functional outcome after delayed administration in a mouse model of diffuse brain injury

A principal mechanism of calcium-mediated neuronal injury is the activation of neutral proteases known as calpains. Proteolytic substrates for calpain include receptor and cytoskeletal proteins, signal transduction enzymes and transcription factors. Recently, calpain inhibitors have been shown to provide benefit in rat models of focal head injury and focal cerebral ischemia. The present study sought to investigate, in experiment 1, the time course of calpain-mediated cytoskeletal injury in a mouse model of diffuse head injury by measuring the 150- and 145-kDa alpha-spectrin breakdown products (SBDP). Secondly, in experiment 2, we examined the effect of early (20 min postinjury) administration of the novel calpain inhibitor SJA6017 on functional outcome measured 24 h following injury and its effect on posttraumatic alpha-spectrin degradation. Lastly, in experiment 3, we examined the effect of delayed (4 or 6 h postinjury) administration of SJA6017 on 24-h postinjury functional outcome. In experiment 1, isoflurane-anesthetized male CF-1 mice (18-22 g) were subjected to a 750 g-cm weight drop-induced injury and were sacrificed for SBDP analysis at postinjury times of 30 min, and 1, 2, 6, 24 and 48 h (plus sham). In experiments 2 and 3, mice were injured as described, and delivered a single tail vein injection of either SJA6017 (0.3, 1, or 3 mg/kg) or vehicle (administered immediately, 4 or 6 h postinjury [3 mg/kg]). Functional outcome was evaluated in both studies, and, in experiment 2, 24-h postinjury assessment of SBDPs was determined. Following injury, the level of SBDP 145 was significantly different from sham at 24 and 48 h in cortical and at 24 h in the hippocampal tissues and at 48 h in the striatum. Immediate postinjury administration of SJA6017 resulted in a dose-related improvement in 24-h functional outcome (p < 0.05 at 3 mg/kg). Significance was maintained after a 4-h delay of the 3 mg/kg, but was lost after a 6-h delay. Despite improvement in functional outcome at 24 h, SJA6017 did not reduce spectrin breakdown in cortical or hippocampal tissues. These results support a role for calpain-mediated neuronal injury and the potential for a practical therapeutic window for calpain inhibition following traumatic brain injury. However, measurements of regional spectrin degradation may not be the most sensitive marker for determining the effects of calpain inhibition.

Concurrent assessment of calpain and caspase-3 activation after oxygen-glucose deprivation in primary septo-hippocampal cultures

The contributions of calpain and caspase-3 to apoptosis and necrosis after central nervous system (CNS) trauma are relatively unexplored. No study has examined concurrent activation of calpain and caspase-3 in necrotic or apoptotic cell death after any CNS insult. Experiments used a model of oxygen-glucose deprivation (OGD) in primary septo-hippocampal cultures and assessed cell viability, occurrence of apoptotic and necrotic cell death phenotypes, and protease activation. Immunoblots using an antibody detecting calpain and caspase-3 proteolysis of alpha-spectrin showed greater accumulation of calpain-mediated breakdown products (BDPs) compared with caspase-3-mediated BDPs. Administration of calpain and caspase-3 inhibitors confirmed that activation of these proteases contributed to cell death, as inferred by lactate dehydrogenase release. Oxygen-glucose deprivation resulted in expression of apoptotic and necrotic cell death phenotypes, especially in neurons. Immunocytochemical studies of calpain and caspase-3 activation in apoptotic cells indicated that these proteases are almost always concurrently activated during apoptosis. These data demonstrate that calpain and caspase-3 activation is associated with expression of apoptotic cell death phenotypes after OGD, and that calpain activation, in combination with caspase-3 activation, could contribute to the expression of apoptotic cell death by assisting in the degradation of important cellular proteins.

Biradicals from benzoenyne-allenes. Application in the synthesis of 11H-benzo[b]fluoren-11-ols, 1H-cyclobut[a]indenes, and related compounds

New synthetic pathways to 11H-benzo[b]fluoren-11-ols, 1H-cyclobut[a]indenes, and related compounds via biradicals generated from benzoenyne-allenes were developed. Treatment of the diacetylenic propargylic alcohols 13, derived from condensation between benzophenones and the lithium acetylide of 1-(2-ethynylphenyl)-2-phenylethyne, with thionyl chloride produced the 11-chloro-11H-benzo[b]fluorene 14 and, after hydrolysis, the corresponding 11H-benzo[b]fluoren-11-ols 15. The transformation involved a sequence of reactions, including a biradical-forming C2-C6 cyclization (Schmittel cyclization) reaction of the chlorinated benzoenyne-allene intermediates followed by an intramolecular radical-radical coupling to form the formal Diels-Alder adducts. Interestingly, in the case of the diacetylenic propargylic alcohol 26, obtained from dibenzosuberenone (25), an intramolecular [2 + 2] cycloaddition reaction of the chlorinated benzoenyne-allene intermediate occurred, furnishing the 1H-cyclobut[a]indene 27 exclusively. The dramatic change of the reaction pathway could be attributed to the emergence of a steric strain due to the nonbonded interactions with the chloro substituent along the pathway toward the formal Diels-Alder adduct 31. On the other hand, the non-chlorinated benzoenyne-allene, derived from prototropic isomerization of the diacetylenic hydrocarbon 60, underwent a formal Diels-Alder reaction to furnish the 11H-benzo[b]fluorene-type hydrocarbon 61 exclusively.