Training facilities in gastrointestinal endoscopy: an animal model as an aid to learning endoscopic ultrasound.

Apart from dedicated fellowships, endoscopic ultrasound (EUS) training comprises "informal" methods, including EUS courses and the use of animal models. We have tried to determine the usefulness of a "hands-on" experience with a live animal model as a teaching strategy for EUS training. In 1997 and 2000 the American Society for Gastrointestinal Endoscopy (ASGE) sponsored hands-on EUS workshops using a live porcine model and participants in these courses were asked to complete a questionnaire about the course (2 years after the 1997 workshop and immediately after the 2000 workshop). The main outcome measurements were the usefulness and quality of the overall course and of the hands-on component in particular, and the effect on EUS practice patterns. Twenty of 38 attendees (53 %) responded to the survey administered 2 years after the 1997 course: 95 % thought the overall course was useful and 85 % valued the hands-on portion; 60 % of respondents had either started performing EUS or, if already experienced in EUS, had increased the number of EUS examinations and/or the complexity of EUS procedures they performed. Of the 34 participants who were at the 2000 ASGE course, over 90 % thought that the course enhanced their EUS skills and 88 % believed that they would be likely to perform EUS in the future. The study was limited in that it did not account for other methods of EUS training that could affect EUS practice patterns and also by the fact that not all the 1997 course participants responded to the questionnaire. In conclusion, live animal models may be a useful adjuctive method for learning EUS skills for the novice or the less experienced endosonographer.

Is endosonography guided fine needle aspiration (EUS-FNA) for sarcoidosis as good as we think?

BACKGROUND: Preliminary data show that endosonography guided fine needle aspiration (EUS-FNA) may be an accurate method for diagnosing sarcoidosis. However, these data were obtained in a small selected group of patients with a very high pretest probability of sarcoidosis. This retrospective study reports on the use of EUS-FNA in an unselected group of patients with mediastinal lymphadenopathy of unknown origin. METHODS: The EUS database of a single tertiary referral centre was reviewed for patients who underwent EUS-FNA for mediastinal lymphadenopathy of unknown origin. Clinical presentation and imaging studies of each case were carefully reviewed and the diagnosis "sarcoidosis" or "no sarcoidosis" attributed if possible. The diagnoses were compared with the result of EUS-FNA. RESULTS: One hundred and twenty four patients were investigated. In 35 cases EUS-FNA identified granulomas (group 1); in the other 89 cases (group 2) no granulomas were detected. The definite diagnoses in group 1 were sarcoidosis (n = 25), indefinite (n = 7), no sarcoidosis (n = 3). The definite diagnoses in group 2 were sarcoidosis (n = 3), indefinite (n = 9), no sarcoidosis (n = 77). Of the 77 cases with no sarcoidosis, 44 were diagnosed with other diseases. The other 33 showed non-specific changes in the FNA and sarcoidosis was excluded by negative non-EUS pathology (n = 17) and clinical presentation. The sensitivity and specificity for EUS-FNA were 89% (95% CI 82 to 94) and 96% (95% CI 91 to 98), respectively, after exclusion of the indefinite cases in both groups. CONCLUSIONS: EUS-FNA is an accurate method for diagnosing sarcoidosis in an unselected group of patients with mediastinal lymphadenopathy. The reported sensitivity and specificity must be appreciated in the context of the difficult and often incomplete clinical diagnosis of sarcoidosis.

Endoscopic ultrasonography in the diagnosis and staging of neoplasms of the head and neck.

BACKGROUND AND STUDY AIMS: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a minimally invasive and highly accurate method of detecting mediastinal lymph-node metastases in gastrointestinal and lung cancer. Little information is available regarding the use of EUS-FNA to stage tumors in the head and neck region. This study reports experience with EUS in the diagnosis and staging of these tumors and their mediastinal spread. PATIENTS AND METHODS: The records of patients who underwent EUS for diagnosis and/or staging of head and neck tumors were reviewed. Referral criteria were suspected invasion of the esophagus by a lower-neck mass on cervical computed tomography (CT) or magnetic resonance imaging (MRI), or mediastinal lymphadenopathy > 10 mm on a chest CT. RESULTS: Thirty-two patients (23 men, nine women; mean age 65 years, range 44 - 80) were referred and underwent 35 EUS examinations. In one patient, EUS was not possible due to a benign esophageal stricture. In 17 patients with suspected esophageal invasion on CT scans, EUS demonstrated invasion of the esophagus in four cases and of the pleura in one; 12 tumors showed no visible invasion of adjacent structures. The other 17 examinations were carried out for suspected mediastinal metastatic disease. In eight cases, EUS-FNA confirmed metastatic disease, whereas only benign changes were shown in the other nine cases. EUS-FNA also provided the first tissue diagnosis in two primary tumors and identified malignancy in one patient with no CT suspicion of positive mediastinal lymph nodes. EUS avoided the need for more invasive investigations in all patients with mediastinal lymphadenopathy, and it changed the management in 12 of the 17 patients (71 %) with suspected esophageal invasion and in eight of the 17 patients (47 %) with suspected mediastinal disease. CONCLUSIONS: EUS with FNA provides a viable approach to the diagnosis and staging of tumors in the head and neck region when there is a suggestion of esophageal invasion on CT or MRI, or enlarged mediastinal lymph nodes. EUS with FNA may avoid the need for mediastinoscopy or other more invasive techniques for staging of these neoplasms.

Comparison of EUS-guided 19-gauge Trucut needle biopsy with EUS-guided fine-needle aspiration.

BACKGROUND AND STUDY AIMS: The accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) depends on immediate specimen review by a cytopathologist. Stromal tumors, lymphoma, and well-differentiated pancreatic cancer are difficult to diagnose on the basis of cytology alone. To overcome these limitations, a 19-gauge Trucut needle has been developed to obtain histological samples at EUS. This pilot study compares the specimen adequacy and diagnostic accuracy of EUS-guided Trucut needle biopsy (EUS-TNB) with EUS-FNA. PATIENTS AND METHODS: A total of 18 patients underwent EUS-TNB and EUS-FNA. The specimen adequacy and diagnostic accuracy of the two techniques was compared. The technical performance and safety profile of the Trucut needle were also evaluated. RESULTS: The EUS-TNB specimen was adequate for evaluation in 15/18 patients compared with 18/18 with EUS-FNA (83 % vs. 100 %, not significant). The diagnostic accuracy of EUS-TNB was not significantly different from EUS-FNA (78 % vs. 89 %). Two complications were encountered: one patient developed mediastinitis and required surgery; another had immediate bleeding that was managed conservatively. One technical problem was encountered: the Trucut needle failed to deploy after two passes when a gastric stromal cell tumor was being biopsied. CONCLUSION: The diagnostic accuracy of the new EUS-TNB is comparable to that of EUS-FNA. In our experience, the overall efficacy and safety profile of the Trucut needle appears modest.

Evaluation of unexplained acute and acute recurrent pancreatitis using endoscopic retrograde cholangiopancreatography, sphincter of Oddi manometry and endoscopic ultrasound.

BACKGROUND AND STUDY AIMS: Unexplained pancreatitis represents a diagnostic challenge. The aim of this study was to determine the diagnostic utility of endoscopic retrograde cholangiopancreatography (ERCP) with sphincter of Oddi manometry (SOM), bile analysis, and endoscopic ultrasound (EUS) in evaluating such patients. PATIENTS AND METHODS: Of 162 patients referred for evaluation of pancreatitis, 72 with a known cause were excluded. The remainder ( n=90) was classified as having prior acute ( n=24) or recurrent acute pancreatitis ( n=66). Bile sampling and SOM were performed at the time of ERCP. EUS was used to assess for tumors and for chronic pancreatitis. Clinical outcomes were evaluated by questionnaire. RESULTS: ERCP was successful in 88/89 patients (99 %). Manometry was successful in 63/67 patients (94 %), and 56 patients underwent EUS. Findings were categorized into five distinct etiologies: sphincter of Oddi dysfunction (SOD) ( n=28; 31 %), pancreas divisum ( n=18; 20 %), biliary ( n=18; 20 %), idiopathic ( n=18; 20 %) and tumor-related ( n=8; 9 %). Features of moderate or severe chronic pancreatitis by EUS and ERCP criteria were found in 18 patients (21 %); an additional nine patients had chronic pancreatitis by EUS criteria alone. EUS identified all the tumors. The condition was improved in 96 % of all patients undergoing endoscopic therapy. CONCLUSION: An etiology was identified in the majority of patients with unexplained pancreatitis. SOD represented the most common finding. Moderate to severe chronic pancreatitis was found in over one-fifth of these patients. Bile analysis, SOM, and EUS are useful tools in the evaluation of unexplained acute pancreatitis.

Alternative non-coding exons support serotonin transporter mRNA expression in the brain and gut.

A number of studies in recent years have linked polymorphisms within the serotonin transporter (5HTT) gene to affective disorders and anxiety traits. The human 5HTT mRNA is alternatively spliced, and the splice variants are equally expressed in the human placental cell line and dorsal raphe. In this study, using 5' rapid amplification of cDNA ends, we show that the rat 5HTT mRNA is alternatively spliced, leading to three distinct mRNAs differing in the 5' untranslated region. To determine whether the three alternatively spliced mRNA species that contain one of the following untranslated regions (i) exon 1A, 63 bp (ii) exon 1A + 1B, 125 bp or (iii) exon 1C, 101 bp, were expressed in a tissue-specific manner, we used RT-PCR and exon-specific oligonucleotide hybridization. Our results suggest two of the variants (1A + 1B and 1A) may utilize the same promoter; however, they are not equally expressed. While in the adult CNS and adrenal medulla, the shorter mRNA consisting of exon 1A was considerably more abundant, in the stomach and heart, the two variants were equally expressed. The third splice variant exon 1C is only expressed in the gut and to a lesser extent in the heart. The data from this study suggest the splice variant consisting of exon 1C may utilize a distinct promoter compared to the other two.

The utility of EUS and EUS-guided fine needle aspiration in detecting celiac lymph node metastasis in patients with esophageal cancer: a single-center experience.

BACKGROUND: The aims of this study were to determine the utility of EUS and EUS-guided fine needle aspiration (EUS-FNA) in the detection and confirmation of celiac lymph node metastasis in patients with esophageal cancer and to define EUS features predictive of celiac lymph node metastasis in these patients. METHODS: The records of 211 patients with esophageal cancer who underwent EUS staging were reviewed. The operating characteristics of EUS were determined in patients where either surgery, EUS-FNA of a celiac lymph node, or both were performed (n = 102). The association between selected variables and the presence of celiac lymph node metastasis was evaluated by univariate and multivariable analyses. RESULTS: EUS in 48 patients provided a true-positive diagnosis of celiac lymph node involvement, a false-positive and false-negative result, respectively, in 6 and 14 patients, and a true-negative diagnosis in 34 patients. The sensitivity of EUS in detecting celiac lymph node was 77% (95% CI [67, 88]), specificity 85% (95% CI [74, 96]), negative predictive value 71% (95% CI [58, 84]), and the positive predictive value 89% (95% CI [81, 97]). EUS-FNA was performed in 94% (51/54) of patients with celiac lymph nodes. The accuracy of EUS-FNA in detecting malignant celiac lymph nodes was 98% (95% CI [90, 100]). Advanced T-stage, the need for dilation, detection of peritumoral lymph nodes, and black race were associated with celiac lymph node involvement. In multivariable analysis, advanced T-stage was the strongest predictor of celiac lymph node involvement. CONCLUSION: EUS and EUS-FNA are highly accurate in detecting and confirming celiac lymph nodes metastasis. Depth of tumor invasion as assessed by EUS is a strong predictor of celiac lymph node metastasis in patients with esophageal cancer.

Randomized controlled trial of EUS-guided fine needle aspiration techniques for the detection of malignant lymphadenopathy.

BACKGROUND: EUS-guided fine needle aspiration (EUS-FNA) is a highly accurate method of detecting malignant lymphadenopathy. The optimal methods for performing EUS-FNA to maximize sensitivity and to minimize the number of needle passes necessary are unknown. This is a report of the results of a prospective randomized controlled trial to determine the effect of suction, the site of FNA (edge or center of lymph node), and the method of preparation of cytologic specimens on accuracy, number of needle passes needed, and specimen quality. METHODS: Consecutive patients with lymphadenopathy detected by EUS underwent FNA. Each lymph node was sampled with or without suction and from the edge or center in a 2 x 2 factorial design. The samples were expressed onto slides for cytology, and the residual material in the needle was analyzed by the cytospin-cellblock technique. Each aspirate was individually characterized for a diagnosis of malignancy, cellularity, and bloodiness. RESULTS: Forty-three patients with a total of 46 lymph nodes were evaluated. The final lymph node diagnosis was benign in 22 (48%), "suspicious for malignancy" in 6 (13%), and malignant in 18 (39%). The use of suction was associated with an increase in the cellularity of the specimen, but did not improve the likelihood of obtaining a correct diagnosis (OR 1.52: 95% CI [0.81, 2.85]). Samples obtained with suction were of worse quality because of excessive bloodiness (OR 4.7: 95% CI [1.99, 11.24]). Aspiration from the edge of the lymph node (compared with the center) did not increase the likelihood of a correct diagnosis (OR 1.16: 95% CI [0.42, 3.21]). For 78% of malignant lymph nodes, the correct diagnosis was obtained on the first needle pass and for 100% by the third pass. Cytospin-cellblock methods did not add any additional diagnostic information compared with direct smear cytology. CONCLUSIONS: The traditional method of applying suction during EUS-FNA does not improve diagnostic accuracy and worsens specimen bloodiness compared with FNA without suction. The site of FNA within the lymph node does not affect accuracy. When EUS-FNA is necessary, our recommendation is up to 3 FNAs without suction from the most convenient and safe location within abnormal-appearing lymph nodes.

An assessment of the potential value of endoscopic ultrasound as a cost-minimizing tool in dyspeptic patients with persistent symptoms.

STUDY AIMS: To quantify resource utilization in dyspeptic patients with persistent symptoms and to determine whether using both the endoscopic and ultrasound capabilities of endoscopic ultrasound could reduce costs. METHODS: Consecutive patients with persistent dyspepsia, after a minimum 1-month trial of acid suppression, underwent endoscopic ultrasound (EUS) and upper endoscopy using the GF-UM20 echo endoscope. Assuming EUS could replace imaging tests which had been requested in addition to upper endoscopy, the hypothetical costs of the EUS-based and upper endoscopy-based strategies were compared. RESULTS: 116 patients with persistent dyspepsia underwent EUS, of whom 64.6 % had > or = 2 imaging procedures, most commonly computed tomography (CT) (70.6 %) and abdominal ultrasound (64.7 %). The number of tests did not correlate strongly with any demographic variables. The fiberoptic echo endoscope provided an adequate endoscopic and ultrasound examination but was damaged by retroflexion. Direct hospital costs were lowest for the EUS-based strategy. Total avoidable cost for 116 patients was $ 4137 to $ 14 121 (or $ 36 to $ 122 per patient), depending on whether upper endoscopy was performed in the non-EUS strategies. CONCLUSIONS: Patients with persistent dyspepsia may undergo multiple abdominal imaging procedures. Clinical variables do not predict the need for additional testing. An EUS-based strategy may reduce overall costs if it prevents additional testing.

Predictors of survival for esophageal cancer patients with and without celiac axis lymphadenopathy: impact of staging endosonography.

BACKGROUND: Esophageal cancer patients with M1a disease are reported to have poor survival. We hypothesized that patients with celiac lymph node metastases (CLN) identified by endoscopic ultrasonography (EUS) would predict a cohort with significantly worse survival postoperatively. Accurate preoperative identification of this group will facilitate future adjuvant studies. METHODS: During the study period, 211 patients with esophageal cancer underwent EUS staging. Patients with evaluable celiac axis (n = 182) were included in this study. Survival of patients with and without CLNs was compared and the factors affecting overall survival were assessed. A subgroup analysis based on CLN status was performed in the subgroup of patients who underwent surgical procedures. RESULTS: Follow-up data was available in 91.2% (166 of 182) of the patients. As staged by EUS, T1, T2, T3, and T4 tumors accounted for 9.3%, 11.5%, 56%, and 21% of the cases, respectively. At least one CLN was imaged by EUS in 40% (72 of 182). The 5-year survival in patients with CLNs detected by EUS was 13% (95% confidence interval, 5% to 21%) compared with 30% (95% confidence interval, 21% to 40%) in patients with no CLNs detected by EUS (p = 0.007). In the subgroup of patients who underwent surgical procedures (n = 68), patients with CLN involvement had worse survival compared with those who did not have malignant involvement of CLNs at the time of their operation (median survival 39.8 versus 13.8 months, p = 0.0008). In a Cox proportional model, adjusting for race and the type of therapy, patients with CLN involvement or advanced EUS American Joint Committee on Cancer stage were more likely to have worse survival (p < 0.05) CONCLUSIONS: EUS base line findings correlate with long term survival in patients with esophageal cancer. Patients with M1a disease as identified by EUS had a significantly worse postoperative survival when compared with non-M1a patients. This cohort of patients will be ideal for the study of induction therapy since the effect of down staging can be assessed before operation.

The reliability of EUS for the diagnosis of chronic pancreatitis: interobserver agreement among experienced endosonographers.

BACKGROUND: Endoscopic ultrasound (EUS) is a minimally invasive, low risk method of diagnosis for chronic pancreatitis (CP). The degree to which endosonographers agree on the features and diagnosis of CP is unknown. For EUS to be considered an accurate test for CP, there must be good interobserver agreement. METHODS: Forty-five pancreatic EUS examinations were videotaped by 3 experienced endosonographers. Examinations from 33 patients with suspected CP based on typical symptoms, as well as 12 control patients without suspected CP, were included. Eleven experienced endosonographers ("experts") who were blinded to clinical information independently evaluated all videotaped examinations for the presence of CP and the following 9 validated features of CP: echogenic foci, strands, lobularity, cysts, stones, duct dilatation, duct irregularity, hyperechoic duct margins, and visible side branches. The experts also ranked (most to least) which features they believed to be the most indicative of CP. Interobserver agreement was expressed as the kappa (kappa) statistic. RESULTS: There was moderately good overall agreement for the final diagnosis of CP (kappa = 0.45). Agreement was good for individual features of duct dilatation (kappa = 0.6) and lobularity (kappa = 0.51) but poor for the other 7 features (kappa < 0.4). The expert panel had consensus or near consensus agreement (greater than 90%) on 206 of 450 (46%) individual EUS features including 22 of 45 diagnoses of CP. Agreement on the final diagnosis of CP was moderately good for those trained in third tier fellowships (kappa = 0.42 +/- 0.03) and those with more than 1100 lifetime pancreatic EUS examinations (kappa = 0.46 +/- 0.05). The presence of stones was regarded as the most predictive feature of CP by all endosonographers, followed by visible side branches, cysts, lobularity, irregular main pancreatic duct, hyperechoic foci, hyperechoic strands, main pancreatic duct dilatation, and main duct hyperechoic margins. The most common diagnostic criterion for the diagnosis of CP was the total number of features (median 4 or greater, range 3 or greater to 5 or greater). CONCLUSIONS: EUS is a reliable method for the diagnosis of chronic pancreatitis with good interobserver agreement among experienced endosonographers. Agreement on the EUS diagnosis of chronic pancreatitis is comparable to other commonly used endoscopic procedures such as bleeding ulcer stigmata and computed tomography of the brain for stroke localization and better than the physical diagnosis of heart sounds.

cDNA expression cloning in mammalian cells.

This unit contains protocols for expression cloning in mammalian cells. Either calcium phosphate- or liposome-mediated transfection of mammalian cells, or virus infection and liposome-mediated transfection are used to screen pools derived from a cDNA library. cDNA pools are prepared for cloning from library-transformed E. coli grown in liquid culture medium or on antibiotic-containing selection plates. Results of screening assays for expression can be detected using autoradiography of dishes of cultured cells to identify clones, direct visualization of radiolabeled cells on emulsion-coated and developed chamber slides, detection and quantification of gene activity by a functional (transport) assay with scintillation counting, or detection using a filter-based assay for binding of radioligand to membranes or whole cells. The most critical step of any cDNA cloning project is the establishment of the screening protocol. Therefore, the bioassay for the gene product must be established prior to executing any of these protocols, including construction of the cDNA library.

Endoscopic ultrasound-guided fine needle aspiration for staging patients with carcinoma of the lung.

BACKGROUND: Endoscopic ultrasound (EUS)-guided fine needle aspiration is a safe, cost-effective procedure that can confirm the presence of mediastinal lymph node metastases and mediastinal tumor invasion. We studied the accuracy of EUS in a large population of lung cancer patients with and without enlarged mediastinal lymph nodes on computed tomographic (CT) scan. METHODS: From 1996 to 2000 all patients referred to our institution with lung tumors and no proven distant metastases were considered for EUS and surgical staging. Patients had endoscopic ultrasound with fine needle aspiration of abnormal appearing mediastinal lymph nodes and evaluation for mediastinal invasion of tumor (stage III or IV disease). Patients without confirmed stage III or IV disease had surgical staging. RESULTS: Two hundred seventy-seven patients met the inclusion criteria, including 121 who had EUS. Endoscopic ultrasound and fine needle aspiration detected stage III or IV disease in 85 of 121 (70%). Among patients with enlarged lymph nodes on CT, 75 of 97 (77%) had stage III or IV disease detected by EUS. Among a small cohort of patients without enlarged mediastinal lymph nodes on CT, 10 of 24 (42%) had stage III or IV disease detected by EUS. For mediastinal lymph nodes only, the sensitivity of endoscopic ultrasound and CT was 87%. The specificity of EUS (100%) was superior to that of CT (32%) (p < 0.001). CONCLUSIONS: Endoscopic ultrasound with fine needle aspiration identified and histologically confirmed mediastinal disease in more than two thirds of patients with carcinoma of the lung who have abnormal mediastinal CT scans. Although mediastinal disease was more likely in patients with an abnormal mediastinal CT, EUS also detected mediastinal disease in more than one third of patients with a normal mediastinal CT and deserves further study. Endoscopic ultrasound should be considered a first line method of presurgical evaluation of patients with tumors of the lung.

CT or EUS for the initial staging of esophageal cancer? A cost minimization analysis.

BACKGROUND: Patients with advanced (T4 and/or M1) esophageal cancer are offered palliative therapy. Computed tomography (CT) is sensitive for distant metastases but is less sensitive than endosonography for T4 disease and celiac lymphadenopathy. The aim of this study was to determine whether initial CT or endosonography costs less to diagnose advanced esophageal cancer. METHODS: A decision model compared the costs of the 2 strategies. Sensitivity analysis and threshold analysis were used to identify the most important determinants of the overall cost of identifying advanced disease. RESULTS: Initial CT is the least costly strategy if the probability of finding advanced disease by initial CT is greater than 20%, if the probability of finding advanced disease by initial endoscopic ultrasound (EUS) is less than 30%, or if the cost of EUS is greater than 3.5 times the cost of CT. However, in our referral center population, endosonography found advanced disease more frequently than CT (44% vs. 13%; p < 0.0001) and the least costly strategy was initial endosonography (expected cost $804 vs. $844). CONCLUSION: CT remains as the initial staging test of choice in most clinical settings. However, in referral centers, initial EUS may be reasonable, but individualized model inputs must be obtained before reliable conclusions can be drawn.

EUS to detect evidence of pancreatic disease in patients with persistent or nonspecific dyspepsia.

BACKGROUND: Mild chronic pancreatitis is difficult to diagnose and the diagnosis is therefore not sought routinely in patients with dyspepsia. The aim of our study was to compare the prevalence of endosonographic pancreatic abnormalities in patients with dyspepsia and control subjects. METHODS: The number of endosonographic abnormalities was compared prospectively in patients with dyspepsia and control patients. Patients in whom there was any suspicion of pancreatic disease were analyzed separately. RESULTS: Between November 1998 and January 1999, 156 patients with dyspepsia were compared with 27 control patients. The groups were similar except that control patients were significantly older and more likely to be men. The mean number of endosonographic abnormalities was higher in dyspeptic patients than in control patients (mean number of abnormalities 3.3: 95% CI [2.9, 3.6] vs. 1.9: 95% CI [0.3, 1.7]). The strongest independent predictors of severe endosonographic abnormalities (defined as 5 or more abnormalities) were the presence of suspected pancreatic disease (odds ratio 7.29: 95% CI [2.03, 26. 14]) and dyspepsia (odds ratio 7.21: 95% CI [1.99, 26.26]). In the dyspepsia group, no clinical variables were significant predictors of severe abnormalities. However, most patients had nonspecific-type dyspepsia or persistent symptoms after therapeutic trials of acid suppression. CONCLUSIONS: Dyspepsia may be an atypical presentation of pancreatic disease in patients with persistent or nonspecific symptoms. Endosonography may be useful to screen for pancreatic disease in patients with persistent dyspepsia.

Imaging of esophageal tumors with a water-filled condom and a catheter US probe.

BACKGROUND: High-frequency catheter ultrasound (C-EUS) probes provide high resolution images of the gastrointestinal tract. Their use in the esophagus is limited by the requirement for a water-filled lumen for good acoustical coupling. We have developed a system using a condom that provides a continuous column of water for high resolution C-EUS imaging of the esophagus. METHODS: Nine patients underwent condom C-EUS for evaluation of esophageal mucosal and submucosal tumors. A standard latex condom was attached to a 2-channel endoscope and filled with water after esophageal intubation. A 20 MHz C-EUS probe placed within the water-filled condom was used to characterize all lesions. RESULTS: The condom C-EUS system provided a 360 degree, high resolution image throughout the length of the esophagus without air artifact and without the risk of aspiration associated with filling the esophageal lumen with water. Complete imaging of the tumor was obtained in all cases, and no additional C-EUS procedures were required. The condom C-EUS was subjectively rated superior overall in comparison to standard C-EUS by 4 independent endosonographers. CONCLUSIONS: Condom C-EUS is a new method of high resolution imaging of the esophagus. This method provides a contained column of water within the esophagus that improves image quality and ease of use and may reduce the risk of aspiration.

Transient expression of a functional serotonin transporter in Merkel cells during late gestation and early postnatal rat development.

We and others have previously identified serotonin transporter mRNA throughout the trigeminal system in the whisker region, trigeminal ganglion, trigeminal nucleus and thalamic relay stations. In order to further implicate a role for the serotonin transporter in this sensory system, we have now characterized serotonin transporter gene expression and function in primary cultures from the rat snout, at several stages of gestation. In this study, we have demonstrated a transient expression of serotonin transporter mRNA in quinacrine-positive Merkel cells between embryonic day 16 and postnatal day 5. Peak levels of mRNA occurred at embryonic day 20 and postnatal day 1. Merkel cells in culture exhibited a transient, antidepressant-sensitive [3H]-serotonin uptake, which was maximal at a time in culture corresponding to embryonic day 22 (day of birth). This transient uptake of serotonin suggests a role for this monoamine during a critical time period of the developing trigeminal sensory system. Regulation of extracellular serotonin levels by transporter activity may reflect the specific formation of the merkel cell-sensory neuron complex in an analogous mechanism by which serotonin modulates synaptogenesis in the central nervous system.

Dilation of malignant esophageal stenosis to allow EUS guided fine-needle aspiration: safety and effect on patient management.

BACKGROUND: Endoscopic ultrasonography (EUS) with fine-needle aspiration identifies patients with esophageal cancer who are unlikely to be cured by surgery. In approximately 30% of patients the staging procedure cannot be completed without dilation of an obstructing tumor. METHODS: All EUS examinations for esophageal cancer requiring dilation from July 1995 to December 1998 were included. Yield was defined as newly diagnosed metastatic (celiac lymph nodes) or locally invasive disease that could not have been detected without dilation. RESULTS: EUS was performed in 132 patients. Forty-two (32%) required 44 dilations. No complications occurred. Of the 42 patients with obstruction, 18 (43%) had celiac adenopathy of which 7 had malignant cells confirmed histologically, 3 had benign adenopathy, and 8 did not undergo fine-needle aspiration due to T4 stage disease (5) or intervening vessels (3). Two patients were upstaged after successful dilation from T2 N1 Mx to T4 N1 Mx and from T3 Nx Mx to T3 N1 M1. Overall, dilation allowed detection of advanced disease in 8 of 42 (19%) patients. Dilation to 11 to 12.8 mm was insufficient (36% success rate) to complete EUS compared with dilation to 14 to 16 mm (87%, p < 0.01). CONCLUSION: Dilation of obstructing esophageal tumors allows identification of a large number of patients with advanced stage malignancy. Dilation to 14 to 16 mm is sufficient for complete staging in almost all patients.