The Origin of P-selectin as a Circulating Plasma Protein

P-selectin is a 140 kD protein found in the α-granules of platelets and the Weibel-Palade bodies of endothelial cells. On cell activation it is expressed on the cell surface and also secreted into plasma. Whether the circulating soluble P-selectin (sP-selectin) originates from platelets, endothelial cells, or both, is not known. We studied the level of sP-selectin in diseases with different platelet counts, with or without evidence of endothelial cell activation. Endothelial cell activation was confirmed by the detection of sE-selectin and EDl-fibronectin. A significant positive correlation between platelet count and sP-selectin concentration was observed in healthy controls, and in patients with thrombocytopenia due to bone marrow aplasia, or with thrombocytosis (r = 0.85; n = 47; p <0.001). In patients with idiopathic thrombocytopenic purpura (ITP) the sP-selectin concentration was 110 ± 39 ng/ml (n = 10), compared to 122 ± 38 ng/ml in healthy controls (n = 26). However, their mean platelet count was lower (58 X 109/1 versus 241 X 109/1 in the control group). Accordingly, the levels of sP-selectin expressed per platelet increased to significantly higher levels (2.0 ± 1.2 versus 0.6 ± 0.2 fg/platelet in the control group-; p <0.0001). This suggests increased platelet turnover in patients with ITP. High levels of sP-selectin were found in patients with sepsis (398 ± 203 ng/ml; n = 15) and with thrombotic thrombocytopenic purpura (TTP; 436 ± 162 ng/ml; n = 12). Compared with patients with ITP, the concentration of sP-selectin per platelet was higher in patients with sepsis (4.8 ± 4.3 fg/platelet; p <0.005) or TTP (17.1 ± 9.5 fg/platelet; p <0.001). Endothelial cells are very likely to be the source in these patients and the presence of endothelial cell activation was confirmed by increased levels of circulating E-selectin and ED 1 -fibronectin.

This study suggests that platelets are the major source of circulating sP-selectin in healthy individuals. Endothelial cell activation is associated with an increased sP-selectin concentration per platelet.

Simulation of macromolecular liquids with the adaptive resolution molecular dynamics technique

We extend the application of the adaptive resolution technique (AdResS) to liquid systems composed of alkane chains of different lengths. The aim of the study is to develop and test the modifications of AdResS required in order to handle the change of representation of large molecules. The robustness of the approach is shown by calculating several relevant structural properties and comparing them with the results of full atomistic simulations. The extended scheme represents a robust prototype for the simulation of macromolecular systems of interest in several fields, from material science to biophysics.

Does the Incidence of Adenocarcinoma of the Esophagus and Gastric Cardia Continue to Rise in the Twenty-First Century?—a SEER Database Analysis

BACKGROUND

The rising incidence and histological change to adenocarcinoma in esophageal cancer over the past four decades has been among the most dramatic changes ever observed in human cancer. Recent reports have suggested that its increasing incidence may have plateaued over the past decade. Our aim was to examine the latest overall and stage-specific trends in the incidence of esophageal adenocarcinoma.

PATIENTS AND METHODS

We used the Surveillance Epidemiology and End Results (SEER) database of the National Cancer Institute to identify all patients with adenocarcinoma of the esophagus and gastric cardia between 1973 and 2009. Both overall and stage-specific trends in incidence were analyzed using joinpoint regression analysis.

RESULTS

The overall incidence of adenocarcinoma of the esophagus and the gastric cardia increased from 13.4 per million in 1973 to 51.4 per million in 2009, a nearly 400 % increase. Jointpoint analysis demonstrated that the yearly increase in incidence has slowed somewhat from 1.27 per million before 1987 to 0.97 between 1987 and 1997 and 0.65 after 1997. Stage-specific analysis suggests that the incidence of noninvasive cancer has actually declined after 2003 with a yearly decrease of 0.22. The percentage of patients diagnosed with in situ cancer declined after 2000 and remained under 2.5 % through the study period.

CONCLUSIONS

The incidence of esophageal adenocarcinoma continues to rise in the USA. The percentage of patients diagnosed with in situ cancer has declined in the twenty-first century.

Time trends and disparities in lymphadenectomy for gastrointestinal cancer in the United States: a population-based analysis of 326,243 patients

BACKGROUND

The value of lymphadenectomy in most localized gastrointestinal (GI) malignancies is well established. Our objectives were to evaluate the time trends of lymphadenectomy in GI cancer and identify factors associated with inadequate lymphadenectomy in a large population-based sample.

METHODS

Using the National Cancer Institute's Surveillance Epidemiology and End Results Database (1998-2009), a total of 326,243 patients with surgically treated GI malignancy (esophagus, 13,165; stomach, 18,858; small bowel, 7,666; colon, 232,345; rectum, 42,338; pancreas, 12,141) were identified. Adequate lymphadenectomy was defined based on the National Cancer Center Network's recommendations as more than 15 esophagus, 15 stomach, 12 small bowel, 12 colon, 12 rectum, and 15 pancreas. The median number of lymph nodes removed and the prevalence of adequate and/or no lymphadenectomy for each cancer type were assessed and trended over the ten study years. Multivariate logistic regression was employed to identify factors predicting adequate lymphadenectomy.

RESULTS

The median number of excised nodes improved over the decade of study in all types of cancer: esophagus, from 7 to 13; stomach, 8-12; small bowel, 2-7; colon, 9-16; rectum, 8-13; and pancreas, 7-13. Furthermore, the percentage of patients with an adequate lymphadenectomy (49 % for all types) steadily increased, and those with zero nodes removed (6 % for all types) steadily decreased in all types of cancer, although both remained far from ideal. By 2009, the percentages of patients with adequate lymphadenectomy were 43 % for esophagus, 42 % for stomach, 35 % for small intestine, 77 % for colon, 61 % for rectum, and 42 % for pancreas. Men, patients >65 years old, or those undergoing surgical therapy earlier in the study period and living in areas with high poverty rates were significantly less likely to receive adequate lymphadenectomy (all p < 0.0001).

CONCLUSIONS

Lymph node retrieval during surgery for GI cancer remains inadequate in a large proportion of patients in the USA, although the median number of resected nodes increased over the last 10 years. Gender and socioeconomic disparities in receiving adequate lymphadenectomy were observed.

Systematic analysis of esophageal pressure topography in high-resolution manometry of 68 normal volunteers

The introduction of high-resolution manometry (HRM) has been a significant advance in esophageal diagnostics. Normative values however are currently based upon a single set of published reference values, and multiple new metrics have been added over the past several years. Our goal was to provide a second set of 'normal-values' and to include all current metrics suggested by the 2012 Chicago classification. Sixty-eight subjects without foregut symptoms or previous surgery (median age 25.5 years, ranging from 20-58 years, 53% female) underwent esophageal motility assessment via an established standardized protocol. Normative thresholds were calculated for esophago-gastric junction (EGJ) characteristics (resting, relaxation, intrabolus pressure, and lengths) as well as for esophageal body strength (contraction amplitudes at multiple levels, distal contractile integral, integrity of peristalsis) and wave propagation (contractile front velocity, distal latency). Overall, our findings where strikingly similar to the previously described metrics derived from 75 control subjects of the Northwestern group. This suggests a high degree of reproducibility of HRM.

Evaluation of esophageal motor function in clinical practice

Esophageal motor function is highly coordinated between central and enteric nervous systems and the esophageal musculature, which consists of proximal skeletal and distal smooth muscle in three functional regions, the upper and lower esophageal sphincters, and the esophageal body. While upper endoscopy is useful in evaluating for structural disorders of the esophagus, barium esophagography, radionuclide transit studies, and esophageal intraluminal impedance evaluate esophageal transit and partially assess motor function. However, esophageal manometry is the test of choice for the evaluation of esophageal motor function. In recent years, high-resolution manometry (HRM) has streamlined the process of acquisition and display of esophageal pressure data, while uncovering hitherto unrecognized esophageal physiologic mechanisms and pathophysiologic patterns. New algorithms have been devised for analysis and reporting of esophageal pressure topography from HRM. The clinical value of HRM extends to the pediatric population, and complements preoperative evaluation prior to foregut surgery. Provocative maneuvers during HRM may add to the assessment of esophageal motor function. The addition of impedance to HRM provides bolus transit data, but impact on clinical management remains unclear. Emerging techniques such as 3-D HRM and impedance planimetry show promise in the assessment of esophageal sphincter function and esophageal biomechanics.

Hiatal hernia and disorders of the spine: a historical perspective

Our understanding of esophageal disease and the foregut has evolved over the past 100 years, especially in recent times. Modern diagnostic technologies and new management paradigms have provided progressive insights into the anatomy, physiology, and normal and abnormal function of the esophagus, as well as improving patient care. Yet, the relationship between the esophagus and its close neighbor, the spine, is rarely discussed and likely underappreciated. Anatomic proximity and intertwined pathophysiology led early investigators to postulate relationships between esophageal disease and spinal abnormalities. More recent studies have illustrated a link between spinal disease and hiatal hernias. Objective radiographic measurements of kyphoscoliosis have correlated with increased hiatal hernia formation. Spinal abnormalities and disease of the esophageal hiatus are becoming more common in our aging population, with each carrying significant risk of morbidity and decreased quality of life. Operative planning and subsequent hiatal hernia repair must be undertaken in the context of these spinal abnormalities. A historical review of past publications related to the subject forms the basis for this publication, thus revealing insight and improving our understanding of the association between spinal abnormalities and hiatal hernias.

Evaluation of the esophagogastric junction using high resolution manometry and esophageal pressure topography

BACKGROUND

The assessment of the esophagogastric junction (EGJ) is the most challenging aspect of clinical esophageal manometry. Although conventional manometric systems can be optimized toward interrogating specific aspects of the EGJ, they are too limited in recording channels and/or fidelity for a comprehensive assessment. The technological advantages inherent in high resolution manometry (HRM) with esophageal pressure topography (EPT) analysis substantially change this equation providing a technology sufficiently robust to dynamically record the contractile activity within the EGJ with both good fidelity and good spatial resolution.

PURPOSE

This review is an update on our understanding of the application of HRM and EPT to the analysis of EGJ function. With respect to sphincter relaxation, the integrated relaxation pressure (IRP) has proven to be a robust metric in differentiating intact from impaired EGJ relaxation. In the process, it revealed that impaired EGJ relaxation could occur not only in the setting of achalasia but also with other causes of EGJ outflow obstruction including hiatus hernia. The morphological description of the EGJ by EPT has also revealed not only a spectrum of abnormality ranging from an intact sphincter to overt herniation, but also the surprise finding of spontaneous conversion among sphincter configurations, emphasizing its dynamic nature. With respect to barrier function, preliminary data have refocused on the crural diaphragm as a key-differentiating feature between preserved and compromised function. Finally, although the accomplishments summarized above are substantial, much work remains to fully exploit the potential of EPT in the clinical characterization of the EGJ.

Immunoglobulins, secretory component, and transferrin in eye secretions of infants in regions with and without endemic trachoma

Eye secretions were collected from Boston and Saudi Arab infants between 1 day and 6 months of age. These secretions were then tested with monospecific antisera in double diffusion and immunoelectrophoresis for the presence of immunoglobulin (Ig)A, IgM, IgG, secretory component, and transferrin. (The term "secretory component" has been chosen by the World Health Organization to replace the terms "secretory piece" and "transport piece.") Eye secretions of all newborns contained secretory component. IgA was found attached to the secretory component in samples from some infants as young as 8 days of age and in samples from most infants over 3 weeks of age. IgG and transferrin were found in most samples regardless of the age of the infant. The prevalence of the respective proteins in the eye secretions of Boston infants was found to be similar to their prevalence in the eye secretions of Saudi Arab infants, including four who developed trachoma during the study. Specific antibody to trachoma was demonstrated in the eye secretions of those infants with active trachoma, and the immunoglobulin class was determined.

Recognition of the alternatively spliced segments of fibronectin by the RCJ 3.1C5.18 chondrocytic rat cell line

OBJECTIVES

To define, for the C5.18 chondrocyte-restricted rat cell line, (1) the capacities for recognition of alternatively spliced segments of the adhesion protein fibronectin (FN), (2) the integrin subunits required for such recognition, and (3) differences in such FN recognition vs the multipotential chondroprogenitor line, RCJ 3.1.

METHODS

C5.18 and RCJ 3.1 cells were tested for their capacities to adhere to recombinant alternatively spliced segments of rat FN, presented on plastic surfaces either in isolation or in partial FNs spanning the 7th through 15th type III repeats (III7-15 FNs). The effects on such adhesion of cations and integrin subunit-specific antibodies were tested.

RESULTS

Despite significant augmentation in chondrocyte-specific gene expression in C5.18 relative to the RCJ 3.1 cells, the two lines exhibited similar recognition of FN spliced segments and partial isoforms. Specifically, both lines adhered to the extra type III repeat A (EIIIA) and V, but not extra type III repeat B (EIIIB), segments. There were different cation and integrin subunit requirements for adhesion to EIIIA vs V segments, and only the V segment was recognized in the context of a III7-15 FN. Such recognition was mediated via a "second" arginine-glycine-aspartic acid (RGD) sequence that is present in the V95 subsegment in rat, but not human, FN.

CONCLUSION

The chondrocyte lineage-committed C5.18 cell line, similar to its multipotential chondroprogenitor, RCJ 3.1, recognizes the "cartilage-restricted" EIIIA and V segments of FN with cation, integrin, and molecular context requirements that are specific to each of these segments.

Future developments in total Barrett's eradication: the surgeon's view

Endoscopic therapies for the treatment of complicated Barret's esophagus should be embraced by the surgical community. While esophagectomy remains the standard of care for early esophageal neoplasia in many centers, endoscopic techniques are being increasingly utilizid. As refinements in both endoscopic and surgical approaches continue to evolve, accurate and contempary assessments of outcomes are critical in assuring that each is applied in appropriate circumstances.

Leptin analog antagonizes leptin effects on food intake and body weight but mimics leptin-induced vagal afferent activation

A recombinantly produced murine leptin analog (MLA) antagonizes leptin-induced signaling in cell lines that express the long form of the leptin receptor. However, the effects of MLA on the activity of leptin-sensitive neurons and on central neural controls of food intake have not been reported. Here we report effects of MLA on food intake and body weight in adult rats and on the activity of cultured rat vagal afferent neurons. Daily intracerebroventricular coinjection of MLA with exogenous leptin significantly attenuated leptin-induced reduction of 48-h food intake and body weight. Coinjection of MLA with leptin also reduced leptin-induced phosphorylation of signal transducer and activator of transcription 3 (STAT3) in the hypothalamus. In addition, chronic intracerebroventricular MLA infusion over 14 d via osmotic minipumps significantly increased daily food intake, rate of body weight gain, fat-pad mass, and circulating plasma leptin concentrations. Surprisingly, however, MLA did not antagonize leptin-evoked increases in cytosolic calcium concentrations in vagal afferent neurons in primary culture. Rather, MLA itself produced acute activation selectively in leptin-responsive vagal afferent neurons. These data suggest that MLA is an antagonist for the central effects of leptin on food intake and body weight but an agonist at sites where leptin induces acute neuronal activation. This mixed antagonist/agonist action suggests either 1) that the coupling of a single leptin receptor (ObRb) to acute activation of neurons occurs by a signaling mechanism different from those that mediate centrally evoked reductions in food intake and body weight or 2) that acute neuronal activation and centrally induced reductions of food intake and body weight are mediated by different leptin receptor subtypes.

Immunotherapy of patients with hormone-refractory prostate carcinoma pre-treated with interferon-gamma and vaccinated with autologous PSA-peptide loaded dendritic cells--a pilot study

PURPOSE

We conducted a pilot trial to assess the feasibility and tolerability of a prime/boost vaccine strategy using interferon-gamma (IFN-gamma) and autologous dendritic cells (DCs) pulsed with HLA-A2-specific prostate-specific antigen (PSA) peptides (PSA-1 [141-150]; PSA-2 [146-156]; PSA-3 [154-163]) for the treatment of 12 patients with hormone refractory prostate carcinoma.

PATIENTS AND METHODS

All patients were vaccinated four times with intracutaneously injected PSA-peptide loaded DCs after subcutaneous administration of IFN-gamma 2 hr before DC administration (50 microg/m(2) body surface). Objectives were safety, clinical benefit, clinical and biochemical response, quality of life, and immunological parameters.

RESULTS

The vaccination was well tolerated without any vaccination-associated adverse events. One partial and one mixed responder were identified, four patients showed stable diseases. Two patients had a decrease and four a slow-down velocity slope in the PSA serum level. All responders showed a positive DTH-response, but only two a slight increase in PSA-peptide specific T-lymphocytes.

CONCLUSION

The immunotherapy with IFN-gamma and PSA-peptide loaded DCs was feasible and well tolerated. The observed responses imply a potential antitumor activity.

Cdx-2 expression in squamous and metaplastic columnar epithelia of the esophagus

The molecular pathogenesis of Barrett's esophagus is poorly understood. Evidence suggests that at a phenotypic level, the metaplastic process begins with the transformation of squamous epithelium in the distal esophagus to cardiac mucosa, which subsequently becomes intestinalized. The homeobox gene Cdx-2 has been shown to be an important transcriptional regulator of embryonic differentiation and maintenance of adult intestinal type epithelium. We hypothesized that Cdx-2 gene expression levels increase with the phenotypic transformation of normal squamous mucosa to the intestinalized columnar mucosa of Barrett's esophagus. Endoscopic biopsies were obtained at the gastroesophageal junction in patients with symptoms of gastroesophageal reflux disease and classified according to histology: normal squamous mucosa (n = 62), cardiac mucosa (n = 19), oxynto-cardiac mucosa (n = 14), and intestinal metaplasia (n = 15). Duodenal biopsies (n = 26) served as the columnar control. After laser capture microdissection and RNA isolation, gene expression levels of Cdx-2 were measured in each tissue type by quantitative reverse transcription polymerase chain reaction. Consistent with its known function, Cdx-2 gene expression levels were highest in duodenal mucosa and nearly absent in squamous epithelium. There was a stepwise increase in Cdx-2 gene expression from cardiac to Barrett's epithelium (P < 0.001). Expression levels of Cdx-2 in cardiac and oxynto-cardiac mucosa were 40-70 times higher and Barrett's mucosa 400 times higher than that found in squamous epithelium. Relative expression of the homeobox gene Cdx-2, known to induce differentiation of intestinal type epithelium, increases in a stepwise fashion during the phenotypic transformation of distal esophageal squamous mucosa to cardiac columnar mucosa and to the intestinalized columnar mucosa of Barrett's esophagus. Therefore, Cdx-2 may be a potential biomarker to detect the early transition to Barrett's esophagus.

The importance of symptom assessment in the surgical treatment of gastroesophageal reflux disease and Barrett's esophagus

The "art" and science of symptom assessment in the evaluation of patients with gastroesophageal reflux disease has been under emphasized. In fact, it is critical to judgements regarding surgical versus non-surgical therapy and is much more difficult than meets the eye. Many symptoms thought to be secondary to gastroesophageal reflux are not, and some, such as asthma cough and chest pain, which are commonly thought secondary to other causes, are indeed symptoms of reflux. Diagnostic studies are helpful but far from perfect, ultimately requiring the clinician's expert judgement as the key factor in determining a successful outcome. The following outlines both an approach to the assessment of symptoms and when possible, clinical studies shedding light on their cause and interpretation.

Bravo capsule induction of esophageal hypercontractility and chest pain

BACKGROUND

The Bravo catheter-free pH monitoring system uses a capsule attached to the esophageal mucosa to detect acid exposure. Placement of the Bravo capsule is associated with intermittent chest pain in 50% of normal volunteers. The authors hypothesized that chest pain in this setting may be attributable to hypertensive esophageal contractions induced by the Bravo capsule.

METHODS

The study population consisted of 40 consecutive patients with reflux symptoms who had stationary esophageal manometry within 1 h after Bravo capsule placement. The control group consisted of 40 patients with symptomatic gastroesophageal reflux disease (GERD) from a population of patients with foregut symptoms who were computer matched to the study group for age, sex, lower esophageal sphincter (LES) pressure, LES length, and 24-h pH composite score. The patients in the control group had manometry before Bravo capsule placement. The occurrence of chest pain was assessed before and during the monitoring period by interview and review of the patient's diary. Mean contraction amplitudes in the distal third of the esophagus after 10 wet swallows were averaged. The prevalence of patients with esophageal contraction amplitudes in the distal third that exceeded the 95th percentile of normal (180 mmHg) and the mean amplitude of distal third esophageal contractions in the study and control populations were compared. In the study group, the incidence of chest pain among the patients with hypercontractility of the esophagus was compared with the incidence among those without hypercontractility.

RESULTS

The mean contraction amplitude was higher in the study group (144.7 vs 105.5 mmHg; p = 0.002). The number of patients with a mean distal esophageal contraction amplitude exceeding the 95th percentile of normal also was significantly higher in the study group (13/40 vs 5/40; p = 0.03). A total of 10 patients experienced new onset of chest pain with the Bravo capsule in place, and 6 patients experienced hypertensive esophageal contractions.

CONCLUSIONS

The intraesophageal Bravo capsule can cause hypertensive esophageal contractions, which may lead to chest pain.

Predictive factors of coexisting cancer in Barrett's high-grade dysplasia

BACKGROUND

Identification of high-grade dysplasia (HGD) in Barrett's esophagus has been considered an indication for esophagectomy because of the high risk for coexisting cancer. However, rigorous endoscopic surveillance programs recently have been recommended, reserving esophagectomy for patients whose cancer is identified on biopsy. This approach risks continued surveillance for patients who already have cancer unless reliable markers for the presence of occult cancer are identified. This study aimed to determine the endoscopic, histologic, and demographic features associated with the presence of occult cancer in patients with HGD.

METHODS

Endoscopic, histologic, and demographic findings for 31 patients who underwent esophagectomy for HGD were reviewed. The presence of an ulcer, nodule, stricture, or raised area on preoperative endoscopy was noted. The results of endoscopic biopsies taken before resection every 1 to 2 cm along the Barrett's segment were reviewed. The HGD was categorized as unilevel if the dysplasia was limited to one level of biopsy and as multilevel if more than one level was involved. Patients were divided into two groups according to the presence or absence of cancer in the resected specimens, and these variables were compared.

RESULTS

The prevalence of coexisting cancer in patients with HGD was 45% (14/31). Of the 31 patients in this study, 9 had a visible lesion. Cancer was found in the resected specimens from 7 (78%) of 9 patients with a visible lesion and 7 (32%) of 22 patients without a visible lesion (p = 0.019). Of 22 patients without a visible lesion, 10 had multilevel and 12 had unilevel HGD. The findings showed that 6 (60%) of 10 patients with multilevel HGD and 1 (8.3%) of 12 patients with unilevel HGD had cancer in the resected esophagus (p = 0.009).

CONCLUSION

For patients with HGD, a lesion visible on endoscopy and/or HGD at multiple biopsy levels is associated with an increased risk for coexisting cancer. These patients should be considered for early esophagectomy.

Leptin and CCK selectively activate vagal afferent neurons innervating the stomach and duodenum

The hormone leptin and the gut peptide CCK synergistically interact to enhance the process of satiation. Although this interaction may occur at several levels of the neuroaxis, our previous results indicate that leptin can specifically enhance the satiation effect of CCK by acting on subdiaphragmatic vagal afferent neurons. Because of this localized action, we hypothesized that a high proportion of vagal afferent neurons innervating the stomach or duodenum would be responsive to leptin and/or CCK. To test this hypothesis, we measured changes in cytosolic calcium levels induced by leptin and CCK in cultured nodose ganglion neurons labeled with a retrograde neuronal tracer injected into either the stomach or the duodenum. In the neurons labeled from the stomach, CCK activated 74% (39 of 53) compared with only 35% (34 of 97) of nonlabeled cells. Of the CCK-responsive neurons 60% (18 of 30) were capsaicin-sensitive. Leptin activated 42% (22 of 53) of the stomach innervating neurons compared with 26% of nonlabeled neurons. All of the leptin-sensitive neurons labeled from the stomach also responded to CCK. In the neurons labeled from the duodenum, CCK activated 71% (20 of 28). Of these CCK-responsive neurons 80% (12 of 15) were capsaicin sensitive. Leptin activated 46% (13 of 28) of these duodenal innervating neurons, of which 89% (8 of 9) were capsaicin-sensitive. Among neurons labeled from the duodenum 43% (12 of 28) were responsive to both leptin and CCK, compared with only 15% (15 of 97) of unlabeled neurons. Our results support the hypothesis that vagal afferent sensitivity to CCK and leptin is concentrated in neurons that innervate the stomach and duodenum. These specific visceral afferent populations are likely to comprise a substrate through which acute leptin/CCK interactions enhance satiation.

Can clinical and endoscopic findings accurately predict early-stage adenocarcinoma?

BACKGROUND

The presentation and management of esophageal cancer are changing, as more patients are diagnosed at an earlier stage of the disease in which endoscopic treatment methods may be contemplated. Therefore, we conducted a study to determine whether symptomatic and endoscopic findings can accurately identify node-negative early-stage adenocarcinoma.

METHODS

A total of 213 consecutive patients (171 men and 42 women) with resectable esophageal adenocarcinoma seen from 1992 to 2002 were evaluated. None of these patients received neoadjuvant chemotherapy or radiation therapy. Using a multivariable model, model-based probabilities of early-stage disease (T1 im/sm N0) were calculated for each combination of the following three features: no dysphagia as main symptom at presentation, tumor length <or=2 cm, and noncircumferential lesion.

RESULTS

Eighty-two percent of the patients with all three characteristics presented with early-stage disease. Even in the setting of small, visible, noncircumferential tumors/nodules in patients without dysphagia, 14% of the patients harbored node metastasis.

CONCLUSIONS

Simple clinical and endoscopic findings predicted early-stage disease in 82% of cases, whereas a small but significant percentage had node metastasis. Because node metastasis predisposes to local failure in nonresectional treatment options such as endoscopic mucosal resection and photodynamic therapy, such findings should have a significant bearing on treatment decisions.

Leptin and CCK modulate complementary background conductances to depolarize cultured nodose neurons

We have previously reported that intraceliac infusion of leptin induces a reduction of meal size that depends on intact vagal afferents. This effect of leptin is enhanced in the presence of cholecystokinin (CCK). The mechanisms by which leptin and CCK activate vagal afferent neurons are not known. In the present study, we have begun to address this question by using patch-clamp electrophysiological techniques to examine the mechanisms by which leptin and CCK activate cultured vagal afferents from adult rat nodose ganglia. We found that leptin depolarized 41 (60%) of 68 neurons. The magnitude of membrane depolarization was dependent on leptin concentration and occurred in both capsaicin-sensitive and capsaicin-insensitive neurons. We also found that a majority (16 of 22; 73%) of nodose neurons activated by leptin were also sensitive to CCK. CCK-induced depolarization was primarily associated with the increase of an inward current (11 of 12), whereas leptin induced multiple changes in background conductances through a decrease in an outward current (7 of 13), an increase in an inward current (3 of 13), or both (3 of 13). However, further isolation of background currents by recording in solutions that contained only sodium or only potassium revealed that both leptin and CCK were capable of increasing a sodium-dependent conductance or inhibiting a potassium-dependent conductance. Our results support the hypothesis that vagal afferents are a point of convergence and integration of leptin and CCK signaling for control of food intake and suggest multiple ionic mechanisms by which leptin and CCK activate vagal afferent neurons.

The safety and usefulness of endoscopy for evaluation of the graft and anastomosis early after esophagectomy and reconstruction

BACKGROUND

Although rare, graft ischemia and necrosis after esophagectomy is a devastating complication. The aim of this study was to review our experience with early endoscopy for evaluation of the graft and anastomosis after esophagectomy and reconstruction.

METHODS

From a population of 479 patients who underwent esophagectomy during the years 1996-2003, we identified 102 patients who had endoscopy within 21 days of operation.

RESULTS

Endoscopy was performed a median of 9 days after operation. Graft ischemia, anastomotic leak, or both were found in 63 of the 102 patients. Reoperation was necessary in 27% of these patients, including graft removal in nine patients. In 39 patients, endoscopy demonstrated a healthy graft; only one of these patients (2.6%) required reoperation. No patient with ischemia judged insufficient to warrant graft removal on initial endoscopy subsequently lost their graft. There were no complications or anastomotic injuries associated with early endoscopy.

CONCLUSION

Endoscopy early after esophagectomy is safe and provides accurate and reliable identification of graft ischemia that can be used to guide the treatment of these patients.

Leptin-induced satiation mediated by abdominal vagal afferents

Leptin is a hormone secreted into the systemic blood primarily by white adipose tissue. However, leptin also is synthesized and stored by cells in the gastric mucosa. Because gastric mucosal leptin is secreted in response to ingestion of a meal, we hypothesized that it might contribute to satiation (meal termination) by acting on gastrointestinal vagal afferent neurons. To test whether leptin is capable of acutely reducing short-term food intake, we measured consumption of a liquid meal (15% sucrose) following low-dose leptin administration via the celiac artery, which perfuses the upper gastrointestinal tract. Leptin (1, 3, 10 μg) was infused via a chronically implanted, nonocclusive celiac arterial catheter or via a jugular vein catheter with its tip in the right cardiac atrium. Fifteen percent sucrose intake was then measured for 30 min. We found that leptin dose dependently inhibited sucrose intake when infused through the celiac catheter but not when infused into the general circulation via a jugular catheter. Plasma leptin concentrations in the general circulation following celiac arterial or jugular leptin infusions were not significantly different. Celiac arterial leptin infusion did not reduce meal size in vagotomized or capsaicin-treated rats. Finally, we also found that reduction of meal size by celiac leptin infusion was markedly enhanced when coinfused with cholecystokinin, a gastrointestinal satiety peptide whose action depends on vagal afferent neurons. Our results support the hypothesis that leptin contributes to satiation by a mechanism dependent on gastrointestinal vagal afferent innervation of the upper gastrointestinal tract.

Esophageal adenocarcinoma in patients < or = 50 years old: delayed diagnosis and advanced disease at presentation

During the past decade, we encountered an increasing number of young patients with esophageal adenocarcinoma. It is not clear whether young patients have more aggressive course and worse prognosis. Our aim was to compare clinicopathological characteristics/treatment results of patients with esophageal adenocarcinoma who were < or = 50 and > 50 years of age. We studied 263 consecutive patients with resectable esophageal adenocarcinoma: 32 (12.1%) were < or = 50 years old. Dysphagia was present in 69 per cent of patients < or = 50 years old and in 48 per cent of older patients (P = 0.019). The median duration of dysphagia was 3.5 months in younger patients compared to 2 months in patients > 50 years (P < 0.0001). Seven of 22 (31.8%) young and three of 108 (2.8%) older patients with dysphagia reported dysphagia for > or = 6 months (P < 0.0001). Fifty per cent of younger patients were stage III/IV and > 70 per cent were node positive (P = 0.04 and P = 0.02 vs patients > 50 years, respectively). Five-year survival was 32.6 per cent for < or = 50 years and 45.5 per cent for > 50 years. More than 10 per cent of esophageal adenocarcinoma patients undergoing surgery are now < or = 50 years of age. They usually present with dysphagia, are symptomatic for a longer time before diagnosis, and have more advanced disease compared to older patients. With appropriate aggressive treatment, survival is similar. Liberal use of endoscopy and aggressive diagnostic approach are paramount in young patients with dysphagia/symptoms of gastroesophageal reflux disease (GERD).

Cooperative activation of cultured vagal afferent neurons by leptin and cholecystokinin

To test the hypothesis that leptin can directly activate vagal afferent neurons, we used fluorescence imaging to detect acute changes in cytosolic calcium after leptin application to primary cultures of vagal afferent neurons dissociated from adult rat nodose ganglia. We found that approximately 40% of vagal afferent neurons exposed to leptin (40 ng/ml) responded with rapid and reversible increases in cytosolic calcium. These responses were dependent upon extracellular calcium. As previously reported, about 35% of vagal afferents increase cytosolic calcium in response to the gut-peptide cholecystokinin (CCK). A majority (74%) of neurons that responded to CCK also exhibited increases in cytosolic calcium in response to leptin. In addition, synergistic increases in cytosolic calcium were observed when leptin and CCK were applied in combination. These results demonstrate that leptin acts directly on vagal afferent neurons to trigger acute influxes of extracellular calcium. Our results also suggest cooperation between leptin and CCK in the activation of some vagal afferent neurons. Acute activation of vagal afferents by leptin alone and in combination with CCK may contribute to modulation of visceral reflexes and control of food intake.

Chronology of the Barrett's metaplasia-dysplasia-carcinoma sequence

The objective of this study was to assess the course over time of the Barrett's metaplasia-dysplasia-carcinoma sequence. The method used was a retrospective analysis of the medical records of a patient series with a median follow-up of 25 months. The study was undertaken in a university hospital foregut laboratory. The progress of seven patients was followed through the sequence of Barrett's esophagus, low-grade dysplasia and high-grade dysplasia to cancer. They all underwent subsequent esophagectomy and were found to have intramucosal adenocarcinoma. The main outcome measure was the time from the first diagnosis of intestinal metaplasia to the development of low-grade dysplasia, high-grade dysplasia and adenocarcinoma. Low-grade dysplasia developed in a median of 24 months, high-grade dysplasia after a median of 33 months and cancer after 36 months. All patients underwent esophagectomy with reconstruction and no patient has had a recurrence at a median follow-up of 25 months (range 10-204 months). Patients on Barrett's surveillance who develop early esophageal adenocarcinoma did so within approximately 3 years after the diagnosis of non-dysplastic Barrett's esophagus.

Correlation of radiographic and manometric findings in patients with ineffective esophageal motility

BACKGROUND

Ineffective esophageal motility disorder (IEM) is a new, manometrically defined, esophageal motility disorder, associated with severe gastroesophageal reflux disease (GERD), GERD-associated respiratory symptoms, delayed acid clearance, and mucosal injury. Videoesophagram is an important, inexpensive, and widely available tool in the diagnostic evaluation of patients with esophageal pathologies. The efficacy of videoesophagography has not been rigorously examined in patients with IEM. The aim of this study was to determine the diagnostic value of videoesophagography in patients with IEM.

METHODS

The radiographic and manometric findings of 202 consecutive patients presenting with foregut symptoms were evaluated. IEM was defined by strict manometric criteria. All other named motility disorders such as achalasia were excluded. Videoesophagography was performed according to a standard protocol.

RESULTS

Of patients in this cohort, 16% (33/202) had IEM by manometric criteria. Of IEM patients, 55% (18/33) had an abnormal videoesophagram, while in 45% (15/33) this test was read as normal. Only 11% (15/137) of patients with a normal videoesophagram were found to have IEM. Sensitivity of videoesophagram was 54.6%, specificity 72.2%, positive predictive value only 27.7%, and negative predictive value 89.1% in the diagnosis of IEM.

CONCLUSIONS

These data show that videoesophagram is relatively insensitive in detecting patients with IEM and should not be considered a valid diagnostic test for this disorder. We conclude that esophageal manometry is an indispensable diagnostic modality in the workup of a patient with suspected of IEM.

Redefining gastroesophageal reflux (GER)

BACKGROUND

The detection of gastroesophageal reflux (GER) has to date been limited to acid exposure observed on 24-h pH monitoring. It is clear, however that nonacid reflux can be a significant clinical problem. Recently, as impedance technology with the capacity to detect all types of reflux (acid, nonacid, liquid, mixed, and air) has been developed.

METHODS

Seventeen asymptomatic healthy volunteers underwent combined 24-h pH and impedance testing. In all patients, pH was measured at 5 cm above the lower esophageal sphincter (LES), and simultaneous impedance changes were recorded at 3, 5, 7, 9, 15, and 17 cm above the LES. Refluxes were classified as acid (drop in pH <4 for >5 sec), Nonacid, short acid, or nonacid delta based on chemical properties; they were further classified as liquid, mixed, or gas based on the physical refluxate detected by impedance changes. The height of the reflux entering the esophagus was classified as distal (<5 cm), intermediate (5-9 cm), or proximal (9-17 cm).

RESULTS

A total of 868 reflux events were characterized. Fifty-nine percent of them were not conventional acid reflux and could only be detected by impedance changes. Less than 2% of the events that were detected by a fall in pH to <4 were not detected by impedance changes. Pure liquid reflux was seen in 35.4%, a mixed pattern in 36.3%, and a gas reflux in 26.7%. Liquid was confined to the distal esophagus in 30%; it reached the midesophagus in 58% and the proximal esophagus in 11%.

CONCLUSIONS

Over half of GER events are not detected by pH studies. Liquid reflux reaches the mid and proximal esophagus 69% of the time and gas nearly always does (92%). The additional information provided by impedance technology is likely to have a major impact on the understanding and clinical management of patients with gastroesophageal reflux disease (GERD).

Lower esophageal sphincter injection of a biocompatible polymer: accuracy of implantation assessed by esophagectomy

BACKGROUND

Endoscopic lower esophageal sphincter (LES) implantation of a biocompatible polymer is undergoing clinical trial as an alternative to pharmacologic and laparoscopic treatments for gastroesophageal reflux disease. The safety and efficacy of LES augmentation depend on accurate placement of the implant into the wall of the esophagus. To date, no study has demonstrated the prevalence and location of the intended implant.

METHODS

The study group consisted of nine patients with underlying esophageal disease severe enough to warrant esophagectomy. Three or four implants of 1 or 2 cc of Enteryx (a biocompatible ethylene-vinyl alcohol copolymer dissolved in dimethyl sulfoxide with micronized tantalum as a radiopaque marker) were placed at the squamocolumnar junction of each patient via a 4-mm, 23-gauge needle under endoscopic guidance. Fluoroscopy was utilized in all patients to facilitate endoscopic placement. Outcome measures included the prevalence and location of successful implantation into the wall of the esophagus.

RESULTS

Thirty of 34 implants (88%) were successfully placed into the wall of the esophagus. The remaining 4 were found lying subserosally or attached to the exterior of the gastroesophageal junction (GEJ). Fluoroscopically, the implants often tended to coalesce, forming arcs or a ring around the GEJ. Histologic examination revealed implantation into the deep submucosa contiguous with the circular muscle and within the muscularis propria in all patients, with implants occasionally extending into the subserosa. There were no untoward reactions identified.

CONCLUSIONS

Endoscopically directed implantation of a biocompatible polymer into the esophageal wall can be accomplished with a high degree of accuracy. Injection via a 4-mm needle results in the placement of material along and within the muscular layers of the esophagus.

Etiology of intestinal metaplasia at the gastroesophageal junction

BACKGROUND

Intestinal metaplasia occurs in the esophagus as a consequence of gastroesophageal reflux disease and in the stomach secondary to H. pylori infection. The etiology of intestinal metaplasia limited to the gastroesophageal junction or cardia (CIM) is disputed. We hypothesized that CIM has dual etiologies: gastroesophageal reflux in some, H. pylori infection in others, and that cytokeratin immunostaining can help to differentiate between these two etiologies.

METHODS

We defined CIM as the presence of intestinal metaplasia within cardiac mucosa on biopsy from an endoscopically normal-appearing gastroesophageal junction. Thirty patients with CIM who had multiple biopsy specimens taken from the esophagus, gastroesophageal junction, and stomach were identified. Tissue blocks from biopsy specimens taken at the gastroesophageal junction were sectioned and immunostained for cytokeratins 7 and 20. The cytokeratin 7/20 staining of the CIM in each patient was determined to be either a Barrett's or non-Barrett's pattern. H. pylori infection was assessed by Giemsa staining of antral biopsy specimens.

RESULTS

H. pylori infection was present in 16 patients. A Barrett's cytokeratin 7/20 staining pattern in the CIM was present in only 46% of the H. pylori-positive patients, as compared to 86% in the 14 patients with CIM and no H. pylori (p = 0.025). Objective evidence of reflux disease was present in 71% of patients with CIM and no H. pylori, as compared to 31% of patients with H. pylori.

CONCLUSIONS

The two different patterns of cytokeratin 7/20 staining found in patients with CIM support the concept of dual etiologies for CIM. A Barrett's staining pattern was associated with objective evidence of gastroesophageal reflux and the absence of H. pylori, suggesting that cytokeratin 7/20 immunostaining is useful to determine the likely etiology of CIM.

Gastro-esophageal reflux disease confined to the sphincter

It has been shown previously that patients with gastro-esophageal reflux disease (GERD) do not always have increased esophageal acid exposure on 24 h pH monitoring. The recent recognition of carditis as a sensitive marker for GERD raises the possibility for patients with mild disease to have normal esophageal acid exposure but inflamed cardiac mucosa on biopsies of the cardia, which may be an early sign of GERD. To test this hypothesis, 171 consecutive patients evaluated for symptoms of GERD and no increased esophageal acid exposure, Barrett's esophagus or erosive esophagitis were divided into those with and without carditis. Esophageal acid exposure and lower esophageal sphincter (LES) characteristics were compared between the two groups. Comparisons were done using the Mann-Whitney U-test for non-parametric data. There were 82 patients with histologic evidence of carditis and 89 patients without carditis. Patients with carditis had a more deteriorated sphincter, determined by overall and abdominal length and resting pressure, and significantly higher esophageal acid exposure (P < 0.05). Patients with symptoms of GERD and histologic evidence of carditis may have early or mild reflux disease, which is confined to the sphincter.

Endoscopic augmentation of the cardia with a biocompatible injectable polymer (Enteryx) in a porcine model

BACKGROUND

Endoscopic approaches to restore the gastroesophageal barrier in patients with gastroesophageal reflux disease (GERD) are presently undergoing clinical trial. The aim of the study was to demonstrate the feasibility, durability, safety, and antireflux efficacy following augmentation of the cardia with a biocompatible injectable polymer (Enteryx).

METHODS

Augmentation was performed in 12 Yucatan mini-pigs. The cardia was injected circumferentially with 1-1.5 ml of Enteryx at three or four sites. Four groups of three animals each were killed at 2, 6, 12, and 24 weeks following augmentation. Gastrointestinal endoscopy and esophageal manometry were performed preoperatively and postoperatively. Competency was determined as the intragastric pressure (yield pressure) and volume (yield volume) needed during gastric distension with air and water to result in equalization of gastric and esophageal pressure. Comparisons were made with a group of noninjected animals (n = 6).

RESULTS

All animals had a normal eating pattern; none showed any evidence of vomiting or regurgitation. The median injection volume was 4 ml (range, 1-8). At autopsy, implants were found in 83% of the animals. Intramuscular placement of the implant was durable, whereas sloughing occurred if the implant was placed submucosally. The mechanical properties of sphincter length and pressure were unaffected by the injection. The median yield pressure of the animals that survived for >6 weeks (21.4 mmHg) was significantly greater (p = 0.049) than the animals that survived for <6 weeks (4.5 mmHg) and greater (p = 0.054) than the control animals (9.1 mmHg), suggesting that the healing process was associated with reduced distensibility of the cardia.

CONCLUSIONS

Augmentation of the cardia with an injectable polymer (Enteryx) is simple, safe, and durable. Early studies suggest that alteration in the distensibility and geometry of the gastroesophageal junction may provide antireflux protection.