Surgical management of acute cholecystitis in a nationwide Danish cohort.

PURPOSE: In the Danish national guidelines from 2006 on the treatment of acute cholecystitis, early laparoscopic operation within 5 days after the debut of symptoms was recommended. The aim of this study was to analyze the outcome in patients with acute cholecystitis subjected to cholecystectomy in Denmark in the five-year period hereafter. METHODS: All patients undergoing cholecystectomy in the period 2006-2010 were registered in the Danish Cholecystectomy Database, from which outcome data were collected. The effect of potential risk factors such as age, gender, BMI, American Society of Anesthesiologists (ASA) score, previous pancreatitis, previous abdominal surgery, year of operation, surgical approach, and surgeon experience was analyzed. RESULTS: Of 33,853 patients registered with a cholecystectomy, 4667 (14%) were operated for acute cholecystitis. In 95% of the patients, laparoscopic cholecystectomy was intended and in 5% primary open access was chosen. The frequency of conversion from laparoscopic to open surgery was 18%. High age and ASA score, operation in the early years of the period, and open or converted procedure all increased the risk of hospital stay to > 3 days or readmission. High age and ASA score, converted or open operation, and previous pancreatitis increased the risk of additional procedures. Postoperative mortality was 1.2%, and significant risk factors for postoperative death were age, low BMI, high ASA score, early year of operation, and open procedures. CONCLUSIONS: Acute cholecystectomy was safely managed laparoscopically in most patients after the introduction of national guidelines, with an increasing rate of laparoscopically completed procedures during the study period.

The uncovering and characterization of a CCKoma syndrome in enteropancreatic neuroendocrine tumor patients.

OBJECTIVE: Neuroendocrine tumors in the pancreas and the gastrointestinal tract may secrete hormones which cause specific syndromes. Well-known examples are gastrinomas, glucagonomas, and insulinomas. Cholecystokinin-producing tumors (CCKomas) have been induced experimentally in rats, but a CCKoma syndrome in man has remained unknown until now. MATERIAL AND METHODS: Using a panel of immunoassays for CCK peptides and proCCK as well as for chromogranin A, we have examined plasma samples from 284 fasting patients with gastroenteropancreatic neuroendocrine tumors. In hyperCCKemic samples, plasma CCK was further characterized by chromatography. RESULTS: One of the patients displayed gross hyperCCKemia. She was a 58-year old woman with a pancreatic endocrine tumor, liver metastases, 500-1000-fold elevated basal CCK concentration in plasma, diarrhea, severe weight loss, recurrent peptic ulcer and bilestone attacks from a contracted gallbladder. The CCK concentrations in plasma were not affected by resection of the pancreatic tumor, but decreased to normal after hemihepatectomy with removal of the metastases. CONCLUSION: A CCKoma syndrome with severe hypersecretion of CCK exists in man. The duodenal ulcer disease and diarrhea with permanently low gastrin in plasma suggest that CCKomas may mimic gastrinoma-like symptoms, because CCK peptides are full agonists of the gastrin/CCK-B receptor.

Less Surgical Experience Has no Impact on Mortality and Morbidity After Laparoscopic Cholecystectomy: A Prospective Cohort Analysis.

BACKGROUND: The number of cholecystectomies required to be fully educated as a surgeon has not yet been established. The European Association for Endoscopic Surgery, however, claims that inadequate experience is a risk factor for bile duct injury. The objective was to investigate surgical experience as a risk factor after laparoscopic cholecystectomy. METHODS: A prospective cohort study using the Danish Cholecystectomy Database to generate a cohort including adults treated with laparoscopic cholecystectomy from 2006 to 2011. The relationship between surgeons' level of experience and outcomes were evaluated. RESULTS: Surgical inexperience was not a risk factor for mortality and morbidity. The risk of conversion was however higher when the patients were operated by more experienced surgeons with an odds ratio of 1.80 (95% confidence interval, 1.51-2.14). Surgical inexperience was not a risk factor for bile duct injury. CONCLUSION: We found that low surgical experience did not by itself increase the risk of mortality or morbidity.

The quality of cholecystectomy in Denmark has improved over 6-year period.

PURPOSE: The Danish Cholecystectomy Database (DCD) was a nationwide quality database that existed from 2006 to 2011. The main goal (indicators) for the database was to increase the quality of cholecystectomy in Denmark by (1) reducing the number of primary open cholecystectomies, (2) increasing the proportion of outpatient surgery, (3) reducing the number of postoperative readmissions, and (4) reducing the number of bile duct injuries and other postoperative complications. The purpose of this study was to evaluate whether the DCD met these goals. METHODS: Data from the DCD were used to identify all patients treated with cholecystectomy in the period from 2006 to 2011. The indicators were analyzed over time as a measure of quality of cholecystectomy and analyzed using chi-square statistics. RESULTS: A total of 37,317 patients were included in the study. The registration rate in the DCD was around 90 %, except in 2011 where it was 70.7 %. The proportion of open cholecystectomies decreased from 2.6 % in 2006 to 0.9 % in 2011 (p < 0.0005). Likewise, in 2011, 80 % of patients undergoing cholecystectomy were discharged within 24 h, an increase compared to 2006 (p < 0.0005). The proportion of readmissions remained steady in the area of 10 % (p = 0.6). Bile duct injuries were low (0.3 %) and unchanged during the study period. CONCLUSION: During the observed 6-year period, a significant increase of laparoscopic procedures was observed with more operations being performed as outpatient procedures. The proportion of readmissions and complications did not increase during this time period.

Hereditary diffuse gastric cancer: updated clinical guidelines with an emphasis on germline CDH1 mutation carriers.

Germline CDH1 mutations confer a high lifetime risk of developing diffuse gastric (DGC) and lobular breast cancer (LBC). A multidisciplinary workshop was organised to discuss genetic testing, surgery, surveillance strategies, pathology reporting and the patient's perspective on multiple aspects, including diet post gastrectomy. The updated guidelines include revised CDH1 testing criteria (taking into account first-degree and second-degree relatives): (1) families with two or more patients with gastric cancer at any age, one confirmed DGC; (2) individuals with DGC before the age of 40 and (3) families with diagnoses of both DGC and LBC (one diagnosis before the age of 50). Additionally, CDH1 testing could be considered in patients with bilateral or familial LBC before the age of 50, patients with DGC and cleft lip/palate, and those with precursor lesions for signet ring cell carcinoma. Given the high mortality associated with invasive disease, prophylactic total gastrectomy at a centre of expertise is advised for individuals with pathogenic CDH1 mutations. Breast cancer surveillance with annual breast MRI starting at age 30 for women with a CDH1 mutation is recommended. Standardised endoscopic surveillance in experienced centres is recommended for those opting not to have gastrectomy at the current time, those with CDH1 variants of uncertain significance and those that fulfil hereditary DGC criteria without germline CDH1 mutations. Expert histopathological confirmation of (early) signet ring cell carcinoma is recommended. The impact of gastrectomy and mastectomy should not be underestimated; these can have severe consequences on a psychological, physiological and metabolic level. Nutritional problems should be carefully monitored.

No difference in incidence of port-site hernia and chronic pain after single-incision laparoscopic cholecystectomy versus conventional laparoscopic cholecystectomy: a nationwide prospective, matched cohort study.

BACKGROUND: Conventional laparoscopic cholecystectomy (CLC) is regarded as the gold standard for cholecystectomy. However, single-incision laparoscopic cholecystectomy (SLC) has been suggested to replace CLC. This study aimed at comparing long-term incidences of port-site hernia and chronic pain after SLC versus CLC. METHODS: We conducted a matched cohort study based on prospective data (Jan 1, 2009-June 1, 2011) from the Danish Cholecystectomy Database with perioperative information and clinical follow-up. Consecutive patients undergoing elective SLC during the study period were included and matched 1:2 with patients subjected to CLC using pre-defined criteria. Follow-up data were obtained from the Danish National Patient Registry, mailed patient questionnaires, and clinical examination. A port-site hernia was defined as a repair for a port-site hernia or clinical hernia located at one or more port sites. RESULTS: In total, 699 patients were eligible and 147 patients were excluded from the analysis due to pre-defined criteria. The rate of returned questionnaires was 83%. Thus, 552 (SLC, n = 185; CLC, n = 367) patients were analyzed. The median observation time was 48 months (range 1-65) after SLC and 48 months (1-64) after CLC (P = 0.940). The total cumulated port-site hernia rate was 4 % and 6 % for SLC and CLC, respectively (P = 0.560). Incidences of moderate/severe chronic pain were 4 % and 5 % after SLC and CLC, respectively (P = 0.661). CONCLUSIONS: We found no difference in long-term incidence of port-site hernia or chronic pain after SLC versus CLC.

Long-term outcome after early repair of iatrogenic bile duct injury. A national Danish multicentre study.

BACKGROUND: The aim of this retrospective study was to evaluate the peri-operative and long-term outcome after early repair with a hepaticojejunostomy (HJ). METHODS: Between 1995 and 2010, a nationwide, retrospective multi-centre study was conducted. All iatrogenic bile duct injury (BDI) sustained during a cholecystectomy and repaired with HJ in the five Hepato-Pancreatico-Biliary centres in Denmark were included. RESULTS: In total, 139 patients had an HJ repair. The median time from the BDI to reconstruction was 5 days. A concomitant vascular injury was identified in 26 cases (19%). Post-operative morbidity was 36% and mortality was 4%. Forty-two patients (30%) had a stricture of the HJ. The median follow-up time without stricture was 102 months. Nineteen out of the 42 patients with post-reconstruction biliary strictures had a re-HJ. Twenty-three patients were managed with percutaneous transhepatic cholangiography and dilation. The overall success rate of re-establishing the biliodigestive flow approached 93%. No association was found between timing of repair, concomitant vascular injury, level of injury and stricture formation. CONCLUSION: In this national, unselected and consecutive cohort of patients with BDI repaired by early HJ we found a considerable risk of long-term complications (e.g. 30% stricture rate) and mortality in both the short- and the long-term perspective.

An evaluation of chromogranin A versus gastrin and progastrin in gastrinoma diagnosis and control.

AIM: The value of chromogranin A (CgA) versus gastrin and progastrin in diagnosis and control of gastrinoma patients is not settled because the peptides circulate as variable mixtures. We have addressed this complexity using defined sequence-specific assays. PATIENTS & METHODS: Six assays were applied to plasma from 40 gastrinoma patients to measure α-amidated gastrins, glycine-extended gastrins, the total progastrin product, and assays for CgA sequence (340-348) and the 'total' CgA product. RESULTS: The gastrin/progastrin parameters did not add to the diagnosis beyond that of α-amidated gastrins, except in one patient. All gastrin parameters correlated otherwise closely. The CgA results differed. Thus, 11 patients had normal CgA concentrations. By contrast, all total CgA concentrations were elevated but correlated only moderately to gastrin. CONCLUSION: Assays measuring α-amidated gastrins have high diagnostic value except for singular patients in whom only progastrin was elevated. By contrast, CgA measurements are not valid in diagnosis or control of gastrinomas.

Cholecystectomy in Danish children--a nationwide study.

BACKGROUND: An increase in the frequency of cholecystectomy in children has been described during the last decades. Part of the reason is that more cholecystectomies in children are performed for dyskinesia of the gallbladder and not only for gallstone disease. We conducted the first nationwide study to describe outcome of cholecystectomies performed in children in Denmark by using data from the national Danish Cholecystectomy Database (DCD). METHODS: In the DCD, two data sources were combined: administrative data from the National Patient Registry (NPR) and clinical data entered into the secure Web site by the surgeon immediately after the operation. In the present analysis, we have included children ≤ 15 years from the five year period January 1, 2006, to December 31, 2010. RESULTS: In the study period 35,444 patients were operated with a cholecystectomy. Of these, 196 (0.5%) were ≤ 15 years. The median age was 14 years, and 82% were girls. Predisposing medical factors for gallstones (despite obesity) were found in only 5%. More than 50% were overweight, and one third were obese. Ninety-seven percent of the operations were completed laparoscopically, and the conversion rate was 0. 5%. Nearly half of the operations (45%) were performed as same day surgery, and 80% of the children stayed in hospital 0-1 day without readmission. 91% were discharged within 3 days and not readmitted. Morbidity was low, and no bile duct lesions occurred. The 30 day mortality was zero. CONCLUSION: Our nationwide outcome results indicate good quality with 91% of the patients discharged within 3 days without readmission, no bile duct injuries, and no mortality. All patients except two were operated for symptomatic gallstone disease in accordance to the Danish national guidelines. We have not experienced a demand or a need to expand the indications for cholecystectomy beyond gallstone disease.

GLP-1 receptor localization in monkey and human tissue: novel distribution revealed with extensively validated monoclonal antibody.

Glucagon-like peptide 1 (GLP-1) analogs are increasingly being used in the treatment of type 2 diabetes. It is clear that these drugs lower blood glucose through an increase in insulin secretion and a lowering of glucagon secretion; in addition, they lower body weight and systolic blood pressure and increase heart rate. Using a new monoclonal antibody for immunohistochemistry, we detected GLP-1 receptor (GLP-1R) in important target organs in humans and monkeys. In the pancreas, GLP-1R was predominantly localized in ß-cells with a markedly weaker expression in acinar cells. Pancreatic ductal epithelial cells did not express GLP-1R. In the kidney and lung, GLP-1R was exclusively expressed in smooth muscle cells in the walls of arteries and arterioles. In the heart, GLP-1R was localized in myocytes of the sinoatrial node. In the gastrointestinal tract, the highest GLP-1R expression was seen in the Brunner's gland in the duodenum, with lower level expression in parietal cells and smooth muscle cells in the muscularis externa in the stomach and in myenteric plexus neurons throughout the gut. No GLP-1R was seen in primate liver and thyroid. GLP-1R expression seen with immunohistochemistry was confirmed by functional expression using in situ ligand binding with (125)I-GLP-1. In conclusion, these results give important new insight into the molecular mode of action of GLP-1 analogs by identifying the exact cellular localization of GLP-1R.

Prophylactic total gastrectomy in hereditary diffuse gastric cancer: identification of two novel CDH1 gene mutations-a clinical observational study.

Inactivating mutations in the CDH1 (E-cadherin) gene are the predisposing cause of gastric cancer in most families with hereditary diffuse gastric cancer (HDGC). The lifetime risk of cancer in mutation positive members is more than 80 % and prophylactic total gastrectomy is recommended. Not all mutations in the CDH1 gene are however pathogenic and it is important to classify mutations before this major operation is performed. Probands from two Danish families with gastric cancer and a history suggesting HDGC were screened for CDH1 gene mutations. Two novel CDH1 gene mutations were identified and found pathogenic. In silico and mini-gene assay were used to predict the functional consequence in one of them. Mutation carriers were offered endoscopy and total gastrectomy. The gastric specimens were completely sectioned and examined histologically. Seven asymptomatic mutation carriers were operated. Hospital stay was 6-8 days and there were no complications. Small foci of diffuse gastric cancer were found in all patients-intramucosal in six and advanced in one. Preoperative endoscopic biopsies had revealed a microscopic cancer focus in two of the patients. Our data confirmed the pathogenic nature of both mutations and strongly support the recommendation of total gastrectomy in asymptomatic CDH1 gene mutation carriers. The functional consequences of novel CDH1 gene mutations with uncertain effects should be tested before correct advice and treatment can be given.

Cholecystectomy for the elderly: no hesitation for otherwise healthy patients.

BACKGROUND: The number of Danish inhabitants older than 65 years is increasing, and cholecystectomy is one of the most common surgical procedures performed for this age group. This study aimed to analyze the role of age as an independent predictor of outcome for elderly cholecystectomy patients. METHODS: Data from the Danish Cholecystectomy Database (2006-2010) were used. The outcomes of interest were conversion rate for laparoscopic cholecystectomy, outpatient rate, postoperative hospital length of stay, readmission rate, and frequency of additional procedures and death within 30 days postoperatively. RESULTS: In this study, 697 patients 80 years of age or older and 4,915 patients ages 65-70 years were compared with 8,805 patients ages 50-64 years. Significantly more patients age 80 years or older underwent surgery for acute cholecystitis, and the conversion rate from laparoscopic to open surgery was significantly higher in the oldest group. The older patients had longer postoperative hospital stays, but nearly 30 % of the patients age 80 years or older were admitted for only 0-1 day and not readmitted, and nearly half of the patients were admitted for only 0-3 days without readmission. Also, the mortality rate and the number of patients who underwent additional procedures within 30 days were higher in the oldest group (6 vs 0.1 and 28 vs 15 %, respectively). A subanalysis of the patients age 80 years or older classified as American Society of Anesthesiology 1 and 2 without acute cholecystitis showed that 44 % left the hospital within 1 day and 63 % within 3 days without readmission and that the 30-day mortality rate was only 2 %. CONCLUSIONS: Age is an independent predictor for worse outcome after cholecystectomy. However, among otherwise healthy patients age 80 years or older who underwent surgery before acute inflammatory complications occurred, 63 % had a fast and uncomplicated course. Thus, it seems fair to recommend elective laparoscopic cholecystectomy when repeated gallstone symptoms have occurred also for the older patient, particularly before the patient experiences acute cholecystitis.

microRNA-146a inhibits G protein-coupled receptor-mediated activation of NF-κB by targeting CARD10 and COPS8 in gastric cancer.

BACKGROUND: Gastric cancer is the second most common cause of cancer-related death in the world. Inflammatory signals originating from gastric cancer cells are important for recruiting inflammatory cells and regulation of metastasis of gastric cancer. Several microRNAs (miRNA) have been shown to be involved in development and progression of gastric cancer. miRNA-146a (miR-146a) is a modulator of inflammatory signals, but little is known about its importance in gastric cancer. We therefore wanted to identify targets of miR-146a in gastric cancer and examine its biological roles. RESULTS: The expression of miR-146a was evaluated by quantitative PCR (qPCR) and found up-regulated in the gastrin knockout mice, a mouse model of gastric cancer, and in 73% of investigated human gastric adenocarcinomas. Expression of miR-146a by gastric cancer cells was confirmed by in situ hybridization. Global analysis of changes in mRNA levels after miR-146a transfection identified two transcripts, caspase recruitment domain-containing protein 10 (CARD10) and COP9 signalosome complex subunit 8 (COPS8), as new miR-146a targets. qPCR, Western blotting and luciferase assays confirmed these transcripts as direct miR-146a targets. CARD10 and COPS8 were shown to be part of the G protein-coupled receptor (GPCR) pathway of nuclear factor-kappaB (NF-kappaB) activation. Lysophosphatidic acid (LPA) induces NF-kappaB activation via this pathway and over-expression of miR-146a inhibited LPA-induced NF-kappaB activation, reduced LPA-induced expression of tumor-promoting cytokines and growth factors and inhibited monocyte attraction. CONCLUSIONS: miR-146a expression is up-regulated in a majority of gastric cancers where it targets CARD10 and COPS8, inhibiting GPCR-mediated activation of NF-kappaB, thus reducing expression of NF-kappaB-regulated tumor-promoting cytokines and growth factors. By targeting components of several NF-kappaB-activating pathways, miR-146a is a key component in the regulation of NF-kappaB activity.

Pitfalls in diagnostic gastrin measurements.

BACKGROUND: Gastrin measurements are performed primarily for the diagnosis of gastrin-producing tumors, gastrinomas, which cause the Zollinger-Ellison syndrome (ZES). Gastrin circulates as several bioactive peptides, however, and the peptide pattern in gastrinoma patients often deviates from normal. Therefore, it is necessary to measure all forms of gastrin. CONTENT: Only immunoassays are useful for measurement of gastrin in plasma. The original assays were RIAs developed in research laboratories that used antibodies directed against the C terminus of gastrin peptides. Because the C-terminal tetrapeptide amide sequence constitutes the active site of gastrin peptides, these assays were well suited for gastrinoma diagnosis. More recently, however, most clinical chemistry laboratories have switched to commercial kits. Because of recent cases of kit-measured normogastrinemia in patients with ZES symptoms, the diagnostic sensitivity and analytical specificity of the available kits have been examined. The results show that gastrin kits frequently measure falsely low concentrations because they measure only a single gastrin form. Falsely high concentrations were also encountered, owing to overreactivity with O-sulfated gastrins or plasma proteins. Thus, more than half of the gastrin kits on the market are unsuited for diagnostics. SUMMARY: Gastrinomas are neuroendocrine tumors, some of which become malignant. A delay in diagnosis leads to fulminant ZES, with major, even lethal, complications. Consequently, it is necessary that the diagnostic sensitivity of gastrin kits be adequate. This diagnostic sensitivity requires antibodies that bind the C-terminal epitope of bioactive gastrins without the influence of O-sulfation.

Processing-independent analysis of peptide hormones and prohormones in plasma.

Peptide hormones are post-translationally matured before they reach a structure in which they can fulfill their biological functions. The prohormone processing may encompass a variety of endoproteolytic cleavages, N- and C-terminal trimmings, and amino acid derivatizations. The same prohormone can be variably processed in different cell types and, in addition, diseased cells often change the processing of a given precursor. The translational process is often either increased or decreased in diseased cells, which renders the ensuing modifications of the prohormone incomplete. Consequently, a variable mixture of precursors and processing-intermediates accumulates in plasma. In order to exploit disturbed posttranslational processing for diagnostic use and at the same time provide an accurate measure of the translational product, a simple analytical principle named "processing-independent analysis" (PIA) was designed. PIA-methods quantitate the total mRNA product irrespective of the degree of processing. PIA-methods have now been developed for a number of prohormones and proteins, and their diagnostic potential appears promising in diagnosis of cardiovascular disease and in several malignancies.

Nationwide quality improvement of cholecystectomy: results from a national database.

OBJECTIVE: To evaluate whether quality improvements in the performance of cholecystectomy have been achieved in Denmark since 2006, after revision of the Danish National Guidelines for treatment of gallstones. DESIGN: A national database that monitors the quality of cholecystectomy was established, and registration of all cholecystectomies in Denmark was mandatory since 1 January 2006. Indicators describing the operation, the postoperative course, the surgical outcome and various risk factors were followed for 4 years. RESULTS: from 2006 were defined as reference values and indicator values, and covariates were stratified by year and tested for trend. Logistic regression models were used to adjust for changes in the prevalence of risk factors/covariates in the study period. SETTING: Nationwide, prospective clinical database in Denmark. Data from 2006 to 2009. PARTICIPANTS: 23,672 patients undergoing cholecystectomy where a laparoscopic procedure was considered the standard operation according to national guidelines. MAIN OUTCOME MEASURES: The rate of conversion from laparoscopic to open operation, the frequency of primary open operations where laparoscopic procedure was the standard, length of postoperative stay including frequency of same-day surgery, additional surgical procedures within 30 days, readmission and mortality. Results Conversion rate and frequency of primary open cholecystectomy were reduced in the study period. Same-day surgery increased by 14.6%, without an increase in readmission rate (9.4%). The frequency of 'additional procedures within 30 days' was also reduced (2.8%). The frequency of injuries requiring reconstructive bile-duct surgery was unaffected (0.15%). CONCLUSION: The study demonstrates nationwide quality improvements of cholecystectomy in Denmark from 2006 to 2009.

miR-449 inhibits cell proliferation and is down-regulated in gastric cancer.

BACKGROUND: Gastric cancer is the fourth most common cancer in the world and the second most prevalent cause of cancer related death. The development of gastric cancer is mainly associated with H. Pylori infection leading to a focus in pathology studies on bacterial and environmental factors, and to a lesser extent on the mechanistic development of the tumour. MicroRNAs are small non-coding RNA molecules involved in post-transcriptional gene regulation. They are found to regulate genes involved in diverse biological functions and alterations in microRNA expression have been linked to the pathogenesis of many malignancies. The current study is focused on identifying microRNAs involved in gastric carcinogenesis and to explore their mechanistic relevance by characterizing their targets. RESULTS: Invitrogen NCode miRNA microarrays identified miR-449 to be decreased in 1-year-old Gastrin KO mice and in H. Pylori infected gastric tissues compared to tissues from wild type animals. Growth rate of gastric cell lines over-expressing miR-449 was inhibited by 60% compared to controls. FACS cell cycle analysis of miR-449 over-expressing cells showed a significant increase in the sub-G1 fraction indicative of apoptosis. ß-Gal assays indicated a senescent phenotype of gastric cell lines over-expressing miR-449. Affymetrix 133v2 arrays identified GMNN, MET, CCNE2, SIRT1 and CDK6 as miR-449 targets. Luciferase assays were used to confirm GMNN, MET, CCNE2 and SIRT1 as direct targets. We also show that miR-449 over-expression activated p53 and its downstream target p21 as well as the apoptosis markers cleaved CASP3 and PARP. Importantly, qPCR analyses showed a loss of miR-449 expression in human clinical gastric tumours compared to normal tissues. CONCLUSIONS: In this study, we document a diminished expression of miR-449 in Gastrin KO mice and further confirmed its loss in human gastric tumours. We investigated the function of miR-449 by identifying its direct targets. Furthermore we show that miR-449 induces senescence and apoptosis by activating the p53 pathway.

The Zollinger-Ellison syndrome and mismeasurement of gastrin.

BACKGROUND & AIMS: Zollinger-Ellison syndrome (ZES) is characterized by hypersecretion of gastric acid, severe peptic ulcerations in the upper small intestine, and diarrhea. It is usually diagnosed by measuring increased levels of gastrin in plasma. METHODS: We examined the accuracy of commercial kits to measure gastrin (7 radioimmunoassays and 5 enzyme-linked immunosorbent assays), using plasma from 40 patients suspected or known to have ZES. Each sample was analyzed using the 12 kits and a reference assay that measures bioactive gastrin in plasma, irrespective of size and amino acid derivatization. Known concentrations of peptides with identical sequences to circulating gastrins were also assessed by all assays. Molecular patterns in plasma from patients with ZES were examined by chromatography and monitored by kits that measure false-low or false-high concentrations of gastrin. RESULTS: Failure to diagnose gastrinomas has serious consequences. Four kits found false-low concentrations of gastrin in 20% to 80% of the patients. Specificity assessment showed that the antibodies used in these kits bound only gastrin-17. Three kits found false-high concentrations of gastrin, because the reagents had increased reactions to sulfated gastrins or to unspecific factors in plasma. Thus, only 5 of 12 kits tested accurately measure plasma concentrations of gastrin. CONCLUSIONS: Seven of 12 tested commercial kits inaccurately measure plasma concentrations of gastrin; these assays used antibodies with inappropriate specificity that were insufficiently validated. Misdiagnosis of gastrinoma based on lack of specificity of assays for gastrin results in ineffective or inappropriate therapy for patients with ZES.