Raman fiber-optical method for colon cancer detection: Cross-validation and outlier identification approach.

Endoscopy plays a major role in early recognition of cancer which is not externally accessible and therewith in increasing the survival rate. Raman spectroscopic fiber-optical approaches can help to decrease the impact on the patient, increase objectivity in tissue characterization, reduce expenses and provide a significant time advantage in endoscopy. In gastroenterology an early recognition of malign and precursor lesions is relevant. Instantaneous and precise differentiation between adenomas as precursor lesions for cancer and hyperplastic polyps on the one hand and between high and low-risk alterations on the other hand is important. Raman fiber-optical measurements of colon biopsy samples taken during colonoscopy were carried out during a clinical study, and samples of adenocarcinoma (22), tubular adenomas (141), hyperplastic polyps (79) and normal tissue (101) from 151 patients were analyzed. This allows us to focus on the bioinformatic analysis and to set stage for Raman endoscopic measurements. Since spectral differences between normal and cancerous biopsy samples are small, special care has to be taken in data analysis. Using a leave-one-patient-out cross-validation scheme, three different outlier identification methods were investigated to decrease the influence of systematic errors, like a residual risk in misplacement of the sample and spectral dilution of marker bands (esp. cancerous tissue) and therewith optimize the experimental design. Furthermore other validations methods like leave-one-sample-out and leave-one-spectrum-out cross-validation schemes were compared with leave-one-patient-out cross-validation. High-risk lesions were differentiated from low-risk lesions with a sensitivity of 79%, specificity of 74% and an accuracy of 77%, cancer and normal tissue with a sensitivity of 79%, specificity of 83% and an accuracy of 81%. Additionally applied outlier identification enabled us to improve the recognition of neoplastic biopsy samples.

Characterization of CA 19-9 bearing mucins as physiological exocrine pancreatic secretion products.

The monoclonal antibody CA 19-9 reacts with a carbohydrate epitope (sialylated lacto-N-fucopentaose II), which was shown to be part of a ganglioside extracted from a colon carcinoma cell line as well as of a mucin isolated from gastrointestinal tract tumor patients' sera. Recently, when we compared CA 19-9 levels in pancreatic juices and corresponding serum samples from a large group of patients, we showed the high serum values to be indicative solely for a malignant disease. In contrast, the overall high CA 19-9 content in pancreatic juices from all diagnostic groups raised the question about the antigenic moieties in these samples. By means of thin layer chromatography of glycolipids with subsequent antibody overlay, gel chromatography, and density gradient analysis, we found only the mucin form in all sources investigated. Thus we conclude that the discrimination potential of the CA 19-9 assay in serum is based on an altered secretion or distribution in pancreatic tumors.

Monoclonal antibody-defined human pancreatic cancer-associated antigens.

Three pancreatic cancer-associated antigens were characterized by use of monoclonal antibodies in immunobinding studies with various cellular and soluble target antigens, in immunoprecipitation, and in immunoperoxidase staining. C54-0 represents a tumor-associated Mr 122,000 antigen, which appears to be widely distributed on various epithelial tumors and to a lower extent on normal tissue. C1-N3 antigen exhibited a more restricted distribution, reacting with pancreatic and various gastrointestinal tract tumors as well as with chronically inflamed pancreatic tissue. The most specific antigen expression was observed for C1-P83 antigen, found on all exocrine tumors of the pancreas, but not on normal or chronically inflamed pancreatic tissue.

Oral capecitabine compared with intravenous fluorouracil plus leucovorin in patients with metastatic colorectal cancer: results of a large phase III study.

PURPOSE: To compare the efficacy and safety of orally administered capecitabine (Xeloda; Roche Laboratories, Inc, Nutley, NJ), a novel fluoropyrimidine carbamate designed to mimic continuous fluorouracil (5-FU) infusion but with preferential activation at the tumor site, with that of intravenous (IV) 5-FU plus leucovorin (5-FU/LV) as first-line treatment for metastatic colorectal cancer. PATIENTS AND METHODS: We prospectively randomized 602 patients to treatment with capecitabine 1,250 mg/m(2) administered twice daily days 1 to 14 every 3 weeks, or to the 4-weekly Mayo Clinic regimen (5-FU/LV) until disease progression or unacceptable toxicity. RESULTS: The primary objective, to demonstrate at least equivalent response rates in the two treatment groups, was met. The overall response rate was 18.9% for capecitabine and 15.0% for 5-FU/LV. In the capecitabine and 5-FU/LV groups, respectively, median time to disease progression was 5.2 and 4.7 months (log-rank P =.65); median time to treatment failure was 4.2 and 4.0 months (log-rank P =.89); and median overall survival was 13.2 and 12.1 months (log-rank P =.33). The toxicity profiles of both treatments were typical of fluoropyrimidines. However, capecitabine led to significantly lower incidences (P <.00001) of stomatitis and alopecia, but a higher incidence of cutaneous hand-foot syndrome (P <.00001). Capecitabine also resulted in lower incidences (P <.00001) of grade 3/4 stomatitis and neutropenia, leading to a lower incidence of grade 3/4 neutropenic fever and sepsis. Only grade 3 hand-foot syndrome (P <.00001) and uncomplicated grade 3/4 hyperbilirubinemia (P <.0001) were reported more frequently with capecitabine. CONCLUSION: Oral capecitabine achieved an at least equivalent efficacy compared with IV 5-FU/LV. Capecitabine demonstrated clinically meaningful safety advantages and the convenience of an oral agent.

Reduced insulinotropic effect of gastric inhibitory polypeptide in first-degree relatives of patients with type 2 diabetes.

In patients with type 2 diabetes, gastric inhibitory polypeptide (GIP) has lost much of its insulinotropic activity. Whether this is similar in first-degree relatives of patients with type 2 diabetes is unknown. A total of 21 first-degree relatives, 10 patients with type 2 diabetes, and 10 control subjects (normal oral glucose tolerance) were examined. During a hyperglycemic "clamp" (140 mg/dl for 120 min), synthetic human GIP (2 pmol. kg(-1). min(-1)) was infused intravenously (30-90 min). With exogenous GIP, patients with type 2 diabetes responded with a lower increment (Delta) in insulin (P = 0.0003) and C-peptide concentrations (P < 0.0001) than control subjects. The GIP effects in first-degree relatives were diminished compared with control subjects (Delta insulin: P = 0.04; Delta C-peptide: P = 0.016) but significantly higher than in patients with type 2 diabetes (P < or = 0.05). The responses over the time course were below the 95% CI derived from control subjects in 7 (insulin) and 11 (C-peptide) of 21 first-degree relatives of patients with type 2 diabetes. In conclusion, a reduced insulinotropic activity of GIP is typical for a substantial subgroup of normoglycemic first-degree relatives of patients with type 2 diabetes, pointing to an early, possibly genetic defect.

Glucagon-like peptide 1 increases secretory burst mass of pulsatile insulin secretion in patients with type 2 diabetes and impaired glucose tolerance.

The insulinotropic gut hormone glucagon-like peptide (GLP)-1 increases secretory burst mass and the amplitude of pulsatile insulin secretion in healthy volunteers without affecting burst frequency. Effects of GLP-1 on secretory mechanisms in type 2 diabetic patients and subjects with impaired glucose tolerance (IGT) known to have impaired pulsatile release of insulin have not yet been studied. Eight type 2 diabetic patients (64+/-9 years, BMI 28.9+/-7.2 kg/m2, HbA1c 7.7+/-1.3%) and eight subjects with IGT (63+/-10 years, BMI 31.7+/-6.4 kg/m2, HbA1c 5.7+/-0.4) were studied on separate occasions in the fasting state during the continued administration of exogenous GLP-1 (1.2 pmol x kg(-1) x min(-1), started at 10:00 P.M. the evening before) or placebo. For comparison, eight healthy volunteers (62+/-7 years, BMI 27.7+/-4.8 kg/m2, HbA1c 5.4+/-0.5) were studied only with placebo. Blood was sampled continuously over 60 min (roller-pump) in 1-min fractions for the measurement of plasma glucose and insulin. Pulsatile insulin secretion was characterized by deconvolution, autocorrelation, and spectral analysis and by estimating the degree of randomness (approximate entropy). In type 2 diabetic patients, exogenous GLP-1 at approximately 90 pmol/l improved plasma glucose concentrations (6.4+/-2.1 mmol/l vs. placebo 9.8+/-4.1 mmol/l, P = 0.0005) and significantly increased mean insulin burst mass (by 68%, P = 0.007) and amplitude (by 59%, P = 0.006; deconvolution analysis). In IGT subjects, burst mass was increased by 45% (P = 0.019) and amplitude by 38% (P = 0.02). By deconvolution analysis, insulin secretory burst frequency was not affected by GLP-1 in either type 2 diabetic patients (P = 0.15) or IGT subjects (P = 0.76). However, by both autocorrelation and spectral analysis, GLP-1 prolonged the period (lag time) between subsequent maxima of insulin concentrations significantly from approximately 9 to approximately 13 min in both type 2 diabetic patients and IGT subjects. Under placebo conditions, parameters of pulsatile insulin secretion were similar in normal subjects, type 2 diabetic patients, and IGT subjects based on all methodological approaches (P > 0.05). In conclusion, intravenous GLP-1 reduces plasma glucose in type 2 diabetic patients and improves the oscillatory secretion pattern by amplifying insulin secretory burst mass, whereas the oscillatory period determined by autocorrelation and spectral analysis is significantly prolonged. This was not the case for the interpulse interval determined by deconvolution. Together, these results suggest a normalization of the pulsatile pattern of insulin secretion by GLP-1, which supports the future therapeutic use of GLP-1-derived agents.

Transesophageal two-dimensional echocardiography in the diagnosis of cor triatriatum in the adult.

Two adult patients with left ventricular inflow obstruction are presented. Conventional two-dimensional echocardiography had failed to yield a definite diagnosis, whereas transesophageal two-dimensional echocardiography clearly documented a membraneous echo structure within the left atrium, diagnostic of cor triatriatum. On the basis of the transesophageal echocardiographic findings, left heart catheterization and angiocardiography were not performed and both patients successfully underwent cardiac surgery.

Phase II trial of 5-fluorouracil and recombinant interferon alfa-2B in metastatic colorectal carcinoma.

Between February 1990 and April 1991, 59 previously untreated patients with progressive and/or symptomatic metastatic colorectal carcinoma were enrolled in a phase II study of 5-fluorouracil (5-FU) and interferon alfa-2b (IFN-alpha). 5-FU 750 mg/m2/day was administered as continuous infusion for 5 days, then weekly in a dose of 750 mg/m2 as intravenous push injection starting on day 15. IFN-alpha 9 MU was given subcutaneously three times a week. Treatment was given for a maximum of 6 months. 55 patients are evaluable for response and 51 for toxicity. 17 patients (31%) achieved a partial remission, 15 (27%) had stable disease and 21 patients (38%) had progressive disease. Median duration of remission was 5 months and median survival for all patients 10 months. Toxicity was important with two treatment-related deaths and severe leukopenia, fever, diarrhoea and mucositis in about one third of the patients. In our opinion, this regimen is effective but rather toxic in metastatic colorectal carcinoma.

Treatment of metastatic colorectal carcinoma with a combination of fluorouracil and recombinant interferon alfa-2b: preliminary data of a phase II study.

From March 1990 to January 1991 52 previously untreated patients with metastatic colorectal carcinoma were enrolled in a phase II study with the combination of interferon alfa-2b and fluorouracil (5-FU). 5-FU 750 mg/m2 per day was administered as continuous infusion for 5 days, then weekly in a dose of 750 mg/m2 as IV push injection starting on day 15. Interferon alfa-2b (Intron A, ESSEX Pharma) 9 x 10(6) units was given subcutaneously three times per week. Response to therapy was evaluated after 3 and 6 months. So far, data on response rates and toxicity are available in 32 patients: partial remission, 10 patients (31%); stable disease, nine patients (28%); progressive disease, 12 patients (37%); toxic deaths, two patients (6%). Projected median survival has not been reached after 11 months. In about one third of the patients severe side effects occurred with leukopenia grade 3 and 4, diarrhea, mucositis and septic complications being the clinically most important. We think that this combination is an effective but toxic regimen in advanced colorectal carcinoma. Further studies must reevaluate both the schedule and the doses of the drugs administered.

Antiproliferative effects exerted by recombinant human tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) on human pancreatic tumor cell lines.

Modulation of the growth of human pancreatic cancer cell lines in vitro by recombinant human tumor necrosis factor-alpha (TNF-alpha) and recombinant human interferon-gamma (IFN-gamma) was investigated. TNF-alpha exerted antiproliferative effects on three of nine pancreatic cancer cell lines and WiDR colorectal cancer cells. When administered together with IFN-gamma TNF-alpha showed enhanced antiproliferative effects on a subset of the pancreatic cancer cell lines tested, including those found to be insensitive to treatment with TNF-alpha alone. Thus the antiproliferative effect achieved by a combined treatment with TNF-alpha and IFN-gamma exceeded that observed with either drug alone in seven of nine pancreatic cancer cell lines.

DU-PAN-2 levels in serum and pancreatic ductal fluids of patients with benign and malignant pancreatic disease.

Previous studies have shown that the DU-PAN-2 antigen is elevated in approximately 70% of serum samples obtained from pancreatic adenocarcinoma patients, and within the normal range (less than 400 U/ml) in 99% of normal subjects. In this study, the DU-PAN-2 antigen level of the serum and pancreatic ductal fluid in patients with malignant pancreatic disease were compared to antigen levels in patients with benign pancreatic diseases. Six percent of patients with chronic pancreatitis and 13% of patients with severe acute pancreatitis had elevated DU-PAN-2 antigen levels in their sera. Pancreatic ductal fluid DU-PAN-2 levels were elevated in 33% (11 of 33) of patients with pancreatic adenocarcinomas, whereas 16% (5 of 31) of patients with chronic pancreatitis and 38% (8 of 21) of control patients had elevated secretion levels. Unlike DU-PAN-2, the tumor markers carcinoembryonic antigen (CEA) and carcinoma (CA) 19-9 were elevated in 90 and 100%, respectively, of secretions of patients with pancreatic adenocarcinoma. However, CEA and CA 19-9 ductal fluid levels were also elevated in patients with chronic pancreatitis (CEA: 61%; CA 19-9: 85%), and therefore these markers are not helpful in distinguishing benign from malignant pancreatic disease. The physiologic implications of elevated DU-PAN-2 serum antigen levels in patients with normal ductal fluid DU-PAN-2 levels are discussed.

Multiparametric tumor marker (CA 19-9, CEA, AFP, POA) analyses of pancreatic juices and sera in pancreatic diseases.

With respect to their diagnostic utility CA 19-9, CEA, AFP and POA were determined in pancreatic secretions and serum of patients suffering from pancreatic cancer (n = 76/55) or chronic pancreatitis (n = 79/45) and of controls (n = 81/42), respectively. While the determination of AFP and POA both in pancreatic secretions and serum does not permit a differential diagnosis, serum CEA (greater than 10 ng/ml) and CA 19-9 (greater than 50 U/ml) levels were indicative of pancreatic cancer in 30% and 83%, respectively, with a rate of false positive results of 5% and 8.5% confined to the chronic pancreatitis patients. A combination of tumor marker analyses, that is, serum CA 19-9 (greater than 50 U/ml) and pancreatic secretion CEA (greater than 70 ng/ml), proved to be positive in 92.9% of tumor patients with a maximum of 10.5% false positives. Likewise, values of serum CA 19-9 (greater than 50 U/ml) and serum CEA (greater than 10 ng/ml) were found in 85.8% of the pancreatic cancer patients with only 8.8% false positives, which were confined to the chronic pancreatitis patients. These results indicate the superiority of multiparametric tumor marker analyses for the diagnosis of pancreatic cancer, especially when including new monoclonal antibody defined tumor markers.

[Colorectal carcinoma: significance of the tumor marker]. / Kolorektales Karzinom: Bedeutung der Tumormarker.

The comparison between carcinoembryonic antigen (CEA) and novel mucin or mucin-like tumour markers in colorectal cancer still favours CEA with regard to sensitivity and specificity. While not contributing to screening and primary diagnostic procedures, its value as a prognostic marker including preoperative staging and post-surgical follow-up, has been well established.

[Practice-relevant intestinal diseases: prevention of colon carcinoma]. / Praktisch wichtige Darmerkrankungen: Kolonkarzinomprophylaxe.

According to the German Statistical Office in Wiesbaden, the number of deaths caused by colorectal cancer in Germany exceeded 30,000 in 1994. Since the prognosis depends heavily on the stage at diagnosis, early recognition is crucial for the further course of the disease. A number of risk groups which would profit from screening programmes have been described for colorectal cancer. It is vitally important to identify these risk groups and to motivate them to undergo regular screening for early diagnosis of carcinoma.

Recent discoveries in cancer genetics of exocrine pancreatic neoplasia.

Within the past 4 years major advances in our understanding of pancreatic carcinogenesis have been made. The discovery of a high frequency of mutations in the tumor suppressor genes p16 and p53 together with an extraordinary high rate of K-ras mutations have shed light on how the disturbance of cell cycle control is a major hallmark in this tumor type. Furthermore, another very recently identified tumor suppressor gene, DPC4 (deleted in pancreatic carcinoma, locus 4), revealed that the TGFbeta-Smad signalling pathway is also likely to contribute to the development of this tumor type. It is now hoped that our improved knowledge of the molecular profile of pancreatic carcinoma will also translate into better diagnostic and therapeutic options to deal with this dismal disease.

[Immunoregulation by the gut-associated immune system]. / Immunregulation durch das darmassoziierte Immunsystem.

The gut associated immune system plays a special regulatory role within the immune system. It governs not only the local IgA response of the gastrointestinal tract but, moreover, gives rise to an antigen specific systemic immune tolerance after enteral application of antigens. This systemic tolerance is suggested to be mediated by lymphatic cells as well as by soluble factors, such as antibodies, immune complexes and suppressor factors, respectively. Very recently published data suggest the existence of an antigen specific, lymphocytic contrasuppressor circuit, which interacts with the well known helper- and suppressor systems within Peyer's plaques thus simultaneously allowing for a local immune response and a systemic tolerance.

Endoscopic ultrasonography (EUS) and fine-needle aspiration (FNA) cytology for diagnosis of chronic pancreatitis.

BACKGROUND AND STUDY AIMS: Previous studies have shown that endoscopic ultrasonography (EUS) sensitively detects morphologic abnormalities due to chronic pancreatitis. However, morphologic EUS findings have limited specificity, particularly at the early stages of chronic pancreatitis. Our aims were to study pancreatic morphology and inflammation in patients with chronic pancreatitis, using EUS and fine-needle aspiration cytology (EUS-FNA), and to compare the results with those of endoscopic retrograde cholangiopancreatography (ERCP) and pancreatic function tests. PATIENTS AND METHODS: 37 patients (48 +/- 13 years) with clinical symptoms and laboratory test findings suggestive of chronic pancreatitis were prospectively studied. Patients with malignancy or major concomitant disorders were excluded. Clinical evaluation included indirect pancreatic function tests. Morphologic criteria for chronic pancreatitis included echo-intense septae/echo-reduced foci (i. e. pseudolobularity), ductal irregularities, and calcifications. EUS-FNA was performed in 27/37 patients, by means of the Hitachi FG34-UX echo endoscope and a 22-gauge needle, and tissue specimens were submitted for standard cytological evaluation. ERCP served as reference in all patients, using the Cambridge classification. RESULTS: 31 patients had chronic pancreatitis while six had normal findings at ERCP. EUS showed morphologic abnormalities of the pancreas in 33 patients. Morphologic abnormalities alone reached a sensitivity of 97 % for chronic pancreatitis with a specificity of only 60 %, while the positive predictive value (PPV) was 94 %, and the negative predictive value (NPV) was 75 %. EUS-FNA increased the negative predictive value to 100 % and the specificity to 67 %. On average, 2.3 needle passes were necessary to obtain sufficient amounts of tissue. The correlation of EUS findings with pancreatic function tests was poor. EUS results were in agreement with regard to the severity of chronic pancreatitis in 5/8 patients with grade I disease, in 11/13 patients with grade II, and in 10/10 patients with grade III disease. Minor complications occurred in two patients (7 %). CONCLUSIONS: EUS is as sensitive and effective as ERCP in the detection of chronic pancreatitis, particularly when only mild disease is present. However, EUS findings have limited specificity, particularly in patients with mild disease. EUS-FNA with cytology is safe and improves the negative predictive value. Negative EUS-FNA findings rule out chronic pancreatitis, but cytological investigation alone does not improve the specificity of EUS findings, suggesting that further improvements in tissue sampling and analysis are necessary to support routine use of FNA in patients with chronic pancreatitis.

[Are Crohn disease and ulcerative colitis the results of an immunoregulatory disturbance?]. / Sind Morbus Crohn und Colitis ulcerosa Folgen einer immunregulatorischen Störung?

The increasing knowledge regarding the regulation of immunological processes has stimulated different approaches to the analysis of chronic inflammatory bowel diseases. The well documented independence of the mucosa-associated immune system favours data obtained analysing immunological reactions within the mucosa. Thus lymphocytes and antibodies isolated from the mucosa are consequently used instead of those obtained from peripheral blood. Despite of an initiation by exogenic agents such as allergenic food constituents for microorganisms there is a growing body of evidence pointing to an immunoregulatory disturbance as underlying pathogenic mechanism for these diseases. This hypothesis is discussed regarding recent observations of a contrasuppressive circuit of regulatory lymphocytes in the murine intestine.