Gastric Serotonin Biosynthesis and Its Functional Role in L-Arginine-Induced Gastric Proton Secretion.

Among mammals, serotonin is predominantly found in the gastrointestinal tract, where it has been shown to participate in pathway-regulating satiation. For the stomach, vascular serotonin release induced by gastric distension is thought to chiefly contribute to satiation after food intake. However, little information is available on the capability of gastric cells to synthesize, release and respond to serotonin by functional changes of mechanisms regulating gastric acid secretion. We investigated whether human gastric cells are capable of serotonin synthesis and release. First, HGT-1 cells, derived from a human adenocarcinoma of the stomach, and human stomach specimens were immunostained positive for serotonin. In HGT-1 cells, incubation with the tryptophan hydroxylase inhibitor p-chlorophenylalanine reduced the mean serotonin-induced fluorescence signal intensity by 27%. Serotonin release of 147 ± 18%, compared to control HGT-1 cells (set to 100%) was demonstrated after treatment with 30 mM of the satiating amino acid L-Arg. Granisetron, a 5-HT3 receptor antagonist, reduced this L-Arg-induced serotonin release, as well as L-Arg-induced proton secretion. Similarly to the in vitro experiment, human antrum samples released serotonin upon incubation with 10 mM L-Arg. Overall, our data suggest that human parietal cells in culture, as well as from the gastric antrum, synthesize serotonin and release it after treatment with L-Arg via an HTR3-related mechanism. Moreover, we suggest not only gastric distension but also gastric acid secretion to result in peripheral serotonin release.

SFRP1 promotor methylation analysis of FTA card touch-prep samples derived from colonic polyps.

Whatman FTA® cards provide the most reliable method for DNA storage and extraction, however, the literature lacks reports on the epigenetic analysis of FTA card-derived tumor DNA. Therefore, this study aimed at demonstrating that punches from colonic adenoma samples preserved on FTA filter cards are suitable for methylation analysis by real-time methylation-specific PCR (MSP). Genomic DNA was isolated from a total of 40 sporadic colorectal adenoma samples stored on FTA cards for a median of 59.60 (range 48-72) months. After bisulfite treatment, deaminated DNA was analyzed by SYBR Green real-time MSP using primers specific for methylated and unmethylated promotor sequences of the secreted frizzled-related protein 1 (SFRP1) gene. Amplifiable DNA could be isolated from all FTA card punches while SFRP1 promotor methylation was present in 34/40 (85.0%) colorectal adenomas. Our results indicate that genomic DNA isolated from colonic tumor samples preserved on FTA cards is suitable for downstream methylation detection methodologies such as MSP even after prolonged storage periods.

Abundance of the Organic Anion-transporting Polypeptide OATP4A1 in Early-Stage Colorectal Cancer Patients: Association With Disease Relapse.

The abundance of OATP4A1 in colorectal cancer (CRC) might be related to tumor progression. This was studied by immunohistochemistry on paraffin-embedded samples obtained from 178 patients (43 patients with a relapse within 5 y) with early-stage CRC. Positivity for OATP4A1 in tumor cells and noncancerous mucosal cells was proved by double-immunofluorescence staining with antibodies against OATP4A1 and keratin 8, whereas antibodies against appropriate CD markers were used to identify immune cells. Automated microscopic image analysis was used to measure the percentage of OATP4A1-positive cells and OATP4A1 staining intensity in tumor, immune, and adjacent normal-looking mucosal cells separately, as well as in the mucosal and immune cells of 14 nonmalignant tissue samples. In CRC the percentage of OATP4A1-positive cells, but not staining intensity, was significantly higher in tumor and mucosal cells adjacent to the tumor compared to the mucosa of nonmalignant samples (P<0.001 each). No difference was registered between immune cells in malignant and nonmalignant samples. Importantly, high levels of OATP4A1 in immune (odds ratio, 0.73; confidence interval, 0.63-0.85; P<0.001), and tumor cells (odds ratio, 0.79; confidence interval, 0.69-0.91; P<0.001) are significantly associated with a low risk of recurrence and also significantly enhance the discriminative power of other clinical parameters [such as International Union Against Cancer (UICC), adjuvant therapy, localization of the primary tumor] of the risk of relapse (receiver operating characteristics analysis; P=0.002). Using an advanced digital microscopic quantification procedure, we showed that OATP4A1 abundance is negatively associated with tumor recurrence in early-stage CRC. This digital scoring procedure may serve as a novel tool for the assessment of potential prognostic markers in early-stage CRC.

Mutual associations between malignancy, age, gender, and subsite incidence of colorectal cancer.

BACKGROUND: A cross-sectional study was performed on a cohort of colorectal cancer (CRC) patients to reveal any influence of age, gender, and subsite on grades of malignancy. PATIENTS AND METHODS: Data from histopathological grading according to WHO criteria were pooled into groups of low-grade (well and moderately differentiated) and high-grade (poorly and undifferentiated) cancer and analyzed for associations. RESULTS: In general, women with CRC were significantly older than men (p<0.05). In particular, women with high-grade cancer in the proximal and distal colon had a median age of 75 years and were thus 10-15 years older (p<0.01 and p<0.05, respectively) than their male counterparts. In contrast, high-grade rectal cancer developed in both genders around the early age of 60 years. CONCLUSION: Women are protected from more aggressive cancer in the colon though not in the rectum until well after menopause. This likely reflects the differential sensitivity of the mucosa at these sites against the anticancer effects triggered by activation of estrogen receptor-beta.

Laparoscopic sleeve gastrectomy as an isolated bariatric procedure: intermediate-term results from a large series in three Austrian centers.

BACKGROUND: Gastric sleeve resection was initially planned as the first step of bilio-pancreatic diversion with duodenal switch but it continues to emerge as a restrictive bariatric procedure on its own. We describe intermediate results in a series of 126 laparoscopic sleeve gastrectomies (LSG) compiled from three bariatric centers in eastern Austria. METHODS: The stomach was laparoscopically reduced to a "sleeve" along the lesser curvature over a 48-Fr bougie. Special attention was placed on complete resection of the gastric fundus. RESULTS: After a mean follow-up of 19.1 months, patients had lost between 2.3 and 27 kg/m(2) or between 6.7% and 130% of their excessive weight. Sixty four percent of the patients lost >50% of their excess weight within an average of 20 months. Seven percent of the patients had an excess weight loss <25% and were therefore considered as failures. The only major surgical complication was leakage of the staple-line needing revision (three times). There were no operative mortalities. CONCLUSION: The final place of LSG in bariatric surgery is still unclear, but our results and those of others show that LSG can be a viable alternative to established procedures.

Differential diagnosis of benign and malign pancreatic masses with 18F-fluordeoxyglucose-positron emission tomography recorded with a dual-head coincidence gamma camera.

INTRODUCTION: Metabolic imaging using 18F-fluordeoxyglucose and a ring-positron emission tomography camera is an established method in the differential diagnosis of pancreatic masses. Ring-positron emission tomography cameras, however, are expensive and available in only few specialized centres. The aim of this study was to investigate how far 18F-fluordeoxyglucose scan with a conventional dual-head gamma-camera could differentiate between benign and malign pancreatic masses. MATERIAL AND METHODS: Forty-one patients (male/female: 25/16; mean age: 64.0 years; range: 41-86 years) with a pancreatic mass detected by ultrasound, computed tomography or MRI were included. In all patients 18F-fluordeoxyglucose scan was performed after overnight fasting and injection of 4 mCi 18F-fluordeoxyglucose using an ADAC Vertex MCD dual head gamma-camera (ADAC; Milpitas, California, USA), equipped with a 5/8-inch NaI-crystal. Images were acquired through a 180 degrees grade rotation in the three dimensional mode. The chosen matrix was 128 x 128 x 16, a Butterworthfilter (ADAC) was used and data were transferred into visible sinograms via Fourier-Rebinning. Coronar, sagittal and transversal slices of 3.9 mm thickness each were acquired. Focal tracer enhancement was suspicious for a malignoma and therefore regarded as positive, diffuse or no tracer uptake was suspicious for a benign process and was regarded as negative for cancer. DEFINITION OF GOLD STANDARDS: A diagnosis of cancer had to be confirmed histologically by specimens obtained by 18G-needle biopsy, surgical resection or at autopsy. A diagnosis of an inflammatory mass was considered proven, if no carcinoma could be found histologically in the surgically resected mass or at autopsy, or if there was no progression of the disease during a follow-up of at least 12 months. RESULTS: In 22 patients carcinoma was diagnosed (pancreatic cancer: n=17; endocrine tumour: n=3; carcinoma of the common bile duct: n=2). 18F-fluordeoxyglucose scan showed a focal tracer enhancement in 19 of these 22 patients (sensitivity: 86.4%). False negative results were acquired in two patients with cancer of the common bile duct and in one patient with poorly controlled insulin-dependent diabetes mellitus. In 19 patients the final diagnosis was an inflammatory pancreatic mass. 18F-fluordeoxyglucose scan showed a diffuse tracer enhancement in 15 of these 19 patients (specificity: 78.9%). False positive results were acquired in three patients whose blood tests showed signs of an acute episode of chronic pancreatitis. Positive and negative predictive values of 18F-fluordeoxyglucose scan were 82.6% and 83.3%, respectively. CONCLUSION: 18F-fluordeoxyglucose scan with a conventional dual-head gamma-camera is a highly sensitive and specific method in the differential diagnosis of benign and malign pancreatic masses.

Treatment of gastro-jejunal leakage and fistulization after gastric bypass with coated self-expanding stents.

Leakage and fistulization of the gastro-jejunostomy have been the major drawback of Roux-en-Y gastric bypass (RYGBP) surgery. Most authors agree that operative treatment is the mainstay of therapy in patients with signs of sepsis. However, intestinal contents causing localized infection may impede healing of sutured leaks in some patients, and fistulas develop. Because the anastomosis cannot be disconnected or exteriorized for anatomical reasons, other forms of treatment have to be applied. The following case-reports describe a technique with implantation of coated self-expanding stents. Leakage of the gastro-jejunostomy occurred in one patient 3 days after RYGBP and resulted in formation of a fistula. A fistula developed in a second patient 63 days after RYGBP. Coated self-extending stents were implanted endoscopically in both patients on postoperative days 19 and 67. Enteral nutrition could be started 6 days later. Stents were removed 2 months after implantation without problems. Weight loss and quality of life 7 and 21 months after stent removal have been excellent in both patients. Implantation of coated self-expanding stents was an effective and minimally invasive option for gastro-jejunal anastomotic fistulas after RYGBP where surgical repair was not possible. In these cases, application of stents allows septic source control without any other intervention.

Band slippage--a potentially life-threatening complication after laparoscopic adjustable gastric banding.

BACKGROUND: Although gastric bands are safe and effective devices, severe late complications may develop in rare cases. PATIENTS: 3 patients were treated for complete dysphagia after slippage of gastric bands. 2 of the patients were admitted for severe dehydration, 1 of whom developed cerebral venous infarction. Ischemia of the gastric pouch occurred in 1 patient. RESULTS: All 3 patients survived after successful medical therapy and surgical removal of the bands. Bariatric reoperations were performed in 2 patients (gastric sleeve resection, gastric bypass). CONCLUSION: Complete dysphagia on the basis of band slippage represents a life-threatening acute event, which may occur even years after implantation. Patients and doctors should be informed about this long-term risk of gastric banding.

Weight loss reduces tissue factor in morbidly obese patients.

OBJECTIVE: To investigate the tissue factor (TF) pathway in clinical obesity and associated metabolic syndrome. RESEARCH METHODS AND PROCEDURES: Thirty-seven morbidly obese patients (4 men; BMI, 48 +/- 7 kg/m(2); range, 42 to 53 kg/m(2)), undergoing elective gastroplasty for the induction of weight loss, were examined for hemostatic, metabolic, and inflammatory parameters at baseline and 14 +/- 5 months postoperatively. RESULTS: Weight loss significantly reduced circulating plasma TF (314 +/- 181 vs. 235 +/- 113 pg/mL, p = 0.04), coagulation factor VII (130 +/- 22% vs. 113 +/- 19%, p = 0.023), and prothrombin fragment F1.2 (2.4 +/- 3.4 vs. 1.14 +/- 1.1 nM, p = 0.04) and normalized glucose metabolism in 50% of obese patients preoperatively classified as diabetic or of impaired glucose tolerance. The postoperative decrease in plasma TF correlated with the decrease of F1.2 (r = 0.56; p = 0.005), a marker of in vivo thrombin formation. In subgroup analysis stratified by preoperative glucose tolerance, baseline circulating TF (402.6 +/- 141.6 vs. 176.2 +/- 58.2, p < 0.001) and TF decrease after gastroplasty (DeltaTF: 164.7 +/- 51.4 vs. -81 +/- 31 pg/mL, p = 0.02) were significantly higher in obese patients with impaired glucose tolerance than in patients with normal glucose tolerance. DISCUSSION: Procoagulant TF is significantly reduced with weight loss and may contribute to a reduction in cardiovascular risk associated with obesity.

High-grade dysplasia and invasive carcinoma in colorectal adenomas: a multivariate analysis of the impact of adenoma and patient characteristics.

BACKGROUND AND AIMS: Most colorectal carcinomas develop from preformed adenomas, but only a minority of adenomas undergo malignant transformation. The clinical significance of polyps of size < 0.5 cm is controversial. The primary goal of this study was to assess the independent risk factors of adenoma and patient characteristics associated with advanced pathological features (APF; i.e. high-grade dysplasia or invasive carcinoma) in colorectal adenomas. A secondary goal was to assess the malignant potential of adenomas with a diameter of < 0.5 cm. PATIENTS AND METHODS: Patients who underwent total colonoscopy at our Medical Department between 1978 and 1996 and had at least one colorectal adenoma were considered for this study. Patients with a history of colorectal cancer, prior polypectomy or colorectal surgery were excluded. A total of 7590 adenomas removed from 4216 patients were included in this analysis. Logistic regression analysis was used to study the impact of different adenoma and patient characteristics on the risk of APF. RESULTS: Size proved to be the most important risk factor for APF. The percentage of adenomas with APF was 3.4%, 13.5% and 38.5% for adenomas of diameter < 0.5 cm, 0.5-1 cm and > 1 cm, respectively. Villous or tubulovillous histology, left-sided location and age >or= 60 years were also associated with APF, whereas sex and number of adenomas had no significant impact. Logistic regression analysis revealed that the risk of an adenoma containing APF was best described by a model incorporating the factors size, location, age, and the age by histology interaction. In the class of adenomas with diameter < 0.5 cm, no invasive carcinoma was found, but 3.4% of adenomas had high-grade dysplasia. CONCLUSIONS: The risk of a colorectal adenoma containing APF can be estimated only by a complex model taking into account several adenoma and patient characteristics. Size, histological type, location and age are independent risk factors for APF in colorectal adenomas. As a considerable percentage of adenomas with diameter < 0.5 cm contain high-grade dysplasia, the clinical conclusion from our study is that all adenomas, including those with diameter < 0.5 cm, should be removed whenever possible.

Surgical treatment for severe acute pancreatitis: extent and surgical control of necrosis determine outcome.

In patients operated on for severe acute pancreatitis (SAP), the factors determining outcome remain unclear. From 1986 to 1998 a total of 340 patients with a diagnosis of SAP and in need of operative treatment were admitted to the intensive care unit (ICU) of a university hospital and a secondary care hospital. The mean APACHE II score on the day of admission was 16.1 (range 8-35). All patients required operative therapy. Among the 340 patients, 270 (79.4%) had to be reoperated: 196 patients (72.6%) underwent operative revisions on demand, and 74 (27.4%) patients had preplanned reoperation. The overall mortality was 39.1% (133 patients). Septic organ failure in 126 patients (37.1%) and myocardial infarction or pulmonary embolism in 7 patients (2%) were the causes of death. The patient's age (p < 0.0002), APACHE II scores at admission (p < 0.0001), presence or development of (single or multiple) organ failure (p < 0.002), infection (p < 0.02) and extent (p < 0.04) of pancreatic necrosis, and surgical control of local necrosis (p < 0.0001) significantly determined survival. SAP that requires surgical treatment is associated with high in-hospital mortality. Surgical control of local necrosis is the precondition for survival. Advanced age of the patient, high APACHE II score at admission, development of organ failure, and the extent and infection of pancreatic necrosis influence the outcome.