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.

Absence of a memory effect for the insulinotropic action of glucagon-like peptide 1 (GLP-1) in healthy volunteers.

BACKGROUND/AIMS: The term memory effect refers to the phenomenon that B cell stimuli retain some of their insulinotropic effects after they have been removed. Memory effects exist for glucose and sulfonylureas. It is not known whether there is a B-cell memory for incretin hormones such as GLP-1. SUBJECTS/METHODS: Eight healthy young volunteers were studied on four occasions in the fasting state. In one experiment, placebo was administered (a). in three more experiments (random order), synthetic GLP-1 (7 - 36 amide) at 1.2 pmol/kg/min was administered over a period of three hours. At 0 min, a bolus of glucose was injected intravenously (0.33 g/kg body weight). GLP-1 was infused from (b). - 60 to 120 min, (c). - 210 to - 30 min, or (d). - 300 to - 120 min. Glucose (glucose oxidase), insulin, C-peptide, GLP-1, and glucagon (immunoassays) were determined. Statistical analysis was carried out by ANOVA and appropriate post hoc tests. RESULTS: GLP-1 plasma levels during the infusion periods were elevated to 89 +/- 9, 85 +/- 13, and 89 +/- 6 pmol/l (p < 0.0001 vs. placebo, 10 +/- 1 pmol/l). Glucose was eliminated faster (p < 0.0001), with an enhanced negative rebound (p = 0.014), and insulin and C-peptide increments were greater after intravenous glucose administration (p < 0.0001) if GLP-1 was administered during the injection of the glucose bolus, but not if GLP-1 had been administered until 120 or 30 min before the glucose load. There was a trend towards higher insulin concentrations (p = 0.056) five minutes after glucose with GLP-1 administered until - 30 min before the glucose load. Glucagon was suppressed by exogenous glucose, but increased significantly (p = 0.013) during the induction of reactive hypoglycemia after glucose injection during GLP-1 administration. CONCLUSION: 1). No memory effect appears to exist for insulinotropic actions of GLP-1, in line with clinical data. 2). Reactive hypoglycemia causes a prompt rise in glucagon despite pharmacological circulating concentrations of GLP-1. 3). Similar studies should be performed in Type 2-diabetic patients, because exposure to GLP-1 might recruit dormant pancreatic B cells to become glucose-competent, and this might contribute to the overall antidiabetogenic effect of GLP-1 in such patients.

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.

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.

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.

Myocardial infarction in diabetic vs non-diabetic subjects. Survival and infarct size following therapy with sulfonylureas (glibenclamide)

AIMS: Sulfonylureas may interfere with 'ischaemic preconditioning' and worsen the prognosis in diabetic patients with acute myocardial infarction. METHODS AND RESULTS: Three hundred and fifty-seven non-diabetic patients admitted with acute myocardial infarction to one hospital over 6.5 years (72 deaths, in-hospital mortality 20.2%) were compared to 245 Type 2 diabetic patients categorized as having taken sulfonylureas (glibenclamide 7+/-3 mg x day(-1); n = 76, 25 deaths = 32.9%;P = 0.025), not having taken sulfonylureas (n = 89, 29 deaths = 33.0%;P = 0.012), and newly diagnosed as having diabetes (n = 80, 20 deaths = 25.0%). Survival was significantly different (log-rank test: P = 0.03). Increments in creatine kinase and creatine kinase(MB)activity were higher in non-diabetic patients (P<0.01). CONCLUSIONS: In-hospital mortality in Type 2 diabetic patients is higher than in non-diabetic patients suffering acute myocardial infarction regardless of whether or not they had been treated with sulfonylureas. Glibenclamide does not enlarge myocardial necroses.

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.

[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.

Glucagon-like peptide 1 inhibition of gastric emptying outweighs its insulinotropic effects in healthy humans.

Glucagon-like peptide 1 (GLP-1) has been shown to inhibit gastric emptying of liquid meals in type 2 diabetic patients. It was the aim of the present study to compare the action of physiological and pharmacological doses of intravenous GLP-1-(7-36) amide and GLP-1-(7-37) on gastric emptying in normal volunteers. Nine healthy subjects participated (26 +/- 3 yr; body mass index 22.9 +/- 1.6 kg/m2; hemoglobin A1C 5.0 +/- 0.2%) in five experiments on separate occasions after an overnight fast. A nasogastric tube was positioned for the determination of gastric volume by use of a dye-dilution technique (phenol red). GLP-1-(7-36) amide (0.4, 0.8, or 1.2 pmol.kg-1.min-1), GLP-1-(7-37) (1.2 pmol.kg-1.min-1), or placebo was infused intravenously from -30 to 240 min. A liquid meal (50 g sucrose, 8% amino acids, 440 ml, 327 kcal) was administered at 0 min. Glucose, insulin, and C-peptide were measured over 240 min. Gastric emptying was dose dependently slowed by GLP-1-(7-36) amide (P < 0.0001). Effects of GLP-1-(7-37) at 1.2 pmol.kg-1.min-1 were virtually identical. GLP.1 dose dependently stimulated fasting insulin secretion (-30 to 0 min) and slightly reduced glucose concentrations. After the meal (0-240 min), integrated incremental glucose (P < 0.0001) and insulin responses (P = 0.01) were reduced (dose dependently) rather than enhanced. In conclusion, 1) GLP-1-(7-36) amide or -(7-37) inhibits gastric emptying also in normal subjects, 2) physiological doses (0.4 pmol.kg-1.min-1) still have a significant effect, 3) despite the known insulinotropic actions of GLP-1-(7-36) amide and -(7-37), the net effect of administering GLP-1 with a meal is no change or a reduction in meal-related insulin responses. These findings suggest a primarily inhibitory function for GLP-1 (ileal brake mechanisms).

A bifunctional HBED-derivative for labeling of antibodies with 67Ga, 111In and 59Fe. Comparative biodistribution with 111In-DPTA and 131I-labeled antibodies in mice bearing antibody internalizing and non-internalizing tumors.

To investigate whether bifunctional ligands containing chelating structures other than EDTA and DTPA and metallic radiotracers other than 111In will reduce the non-specific radioactivity uptake in the liver during immunoscintigraphy, we synthetized an isothiocyanato-substituted phenolic polyaminocarboxylic acid (HBED-CI) for labeling of MAbs with 67Ga, 111In and 59Fe. Biodistribution of HBED-CI-labeled MAbs was compared to that of 131I and 111In-DTPA labeled MAbs in nude mice bearing tumors, which differ with regard to intracellular internalization and catabolism of the corresponding MAb-antigen complex. In the liver a continuous radioactivity excretion for 67Ga-HBED-CI-labeled MAbs was observed with kinetics that parallel 131I clearance after administration of 131I-MAbs, while 111In-HBED-CI-labeling led to a constant 111In liver level quite similar to that of 111In-DTPA-MAbs. In tumors, 67Ga-HBED-CI-MAb uptake again paralleled that of 131I-MAbs, showing continuous accumulation in tumor tissues when internalization of the MAb-antigen complex was not involved. A much lower uptake, which peaked between 24 and 48 h, was found in the case of MAb-antigen internalization. 111In of 111In-HBED-CI- and 111In-DTPA-labeled MAbs continuously accumulated in both types of tumors. Compared with 111In-DTPA-MAbs, an improvement in tumor-to-liver ratios, due to the reduced liver radioactivity associated with 67Ga-HBED-CI-labeled MAbs, could only be obtained with non-internalizing tumors. The time course of radioactivity distribution in the liver and in MAb-internalizing tumors after administration of 67Ga-HBED-CI-, 111In-HBED-CI- and 111In-DTPA-labeled MAbs further indicates a dominating influence of the metallic radiotracer rather than the ligand on retention or excretion of radioactivity in MAb-catabolizing tissues.

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.