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The case of a 59-year-old man with a history of recurrent severe gastrointestinal bleeding due to Meckel's diverticulum is described. The diagnosis was achieved by means of capsule endoscopy. The histological examination revealed the presence of Meckel's diverticulum with ectopic gastric mucosa. The use of capsule endoscopy for the detection of Meckel's diverticulum is discussed.

To evaluate pancreatic exocrine function in uremia, 25 patients undergoing regular hemodialysis without clinical evidence of pancreatic disease and 25 healthy control subjects were studied by fecal elastase 1 and chymotrypsin. Abdominal ultrasonography and measurement of serum lipase, calcium, phosphate, and parathormone were also carried out. Fecal elastase was significantly lower (P0.001) in patients than in controls. Abnormally low values were found in 12/25 patients of whom six had values100 microg/g. Fecal chymotrypsin was significantly lower (P0.05) in patients than in controls, with lower than normal values found in 10/25 patients. Fecal elastase was not related to the serum calcium, phosphate, or parathormone levels or to the period of dialysis. In patients serum lipase was normal or slightly elevated (300 units/liter), and there was no evidence of pancreatic disease at ultrasound examination. The results lend further support to the existence of pancreatic function impairment in a significant number of patients with renal failure despite the absence of clinical and morphological evidence of pancreatic disease.

Available assays for measurement of pancreatic isoamylase in serum based on specific immunoinhibition of salivary fraction are unable to detect macroamylase. We combined a polyethylene glycol test which identifies macroamylase by selective precipitation with an automated assay for total amylase and pancreatic isoamylase measurement.We analysed 24 sera proven positive for macroamylase using gel filtration chromatography and 80 negative sera. Precipitation of macroamylase with polyethylene glycol, colourimetric measurement of total amylase activity and immunoinhibition for the determination of pancreatic isoamylase were carried out.Macroamylasaemic sera showed precipitation of at least 71% of the amylase activity, while sera with normal-sized amylase exhibited a maximum of 61%. In all the macroamylasaemic sera but two, the immunoinhibition test showed a rise in pancreatic isoamylase, which was found to be the prevalent fraction in 16. In 21 out of 24 sera with macroamylase and 67 out of 80 with normal-sized amylase, the precipitated amylase activity was also measured after immunoinhibition of non pancreatic activity. In macroamylasaemic sera, the percentage of precipitated pancreatic isoamylase activity ranged from 75% to 98%, while in samples with normal-sized amylase it was less than 71%.Polyethylene glycol precipitation can easily be combined with automated assays for the determination of pancreatic isoamylase and should be carried out whenever dealing with hyperamylasaemia of unclear origin.

Gastrointestinal bleeding is a frequent complication in hemodialysis patients; angiodysplasia is a potential cause, with a higher incidence in uremic patients. We describe a case of severe anemia (Hemoglobin up to 3.5 g/dl) secondary to diffuse angiodysplastic lesions in a hemodialysis patient with mixed connective tissue disease. The case is characterised both by the severity of the clinical picture (extension and entity of angiodysplastic lesions, frequency of bleeding episodes) and by the patient's religious faith which made her reject blood transfusions. We underline the efficacy of estrogen-progesterone therapy in view of the modest results obtained with other therapeutic strategies on bleeding.

This study assessed the diagnostic accuracy of fecal elastase 1 in chronic pancreatitis. Fifty-three healthy subjects, 44 patients with chronic pancreatitis (22 severe, 13 moderate, and 9 mild), and 43 patients with nonpancreatic digestive disease were studied. Elastase 1 concentration was determined on a small sample of feces using a commercially available kit. Fecal chymotrypsin was also measured. With a cutoff level of 190 microg/g, all healthy controls except one (98.1%), and the majority of patients with nonpancreatic digestive diseases (40 of 43; 93.0%) had elastase values above this limit. Among the 44 patients with chronic pancreatitis, 34 (77.3%) had pathological values: all 22 (100%) with severe disease, 10 of 13 (76.9%) with moderate disease and 2 of 9 (22.2%) with mild disease. Chymotrypsin values were pathological in 25 of 44 (56.8%) patients with chronic pancreatitis: 17 of 22 (77.2%) with severe pancreatitis, 7 of 13 (53.8%) with moderate pancreatitis, and 1 of 9 (11.1%) with mild disease. The specificity was 95.8% for elastase 1 and 85.4% for chymotrypsin. The difference both in sensitivity and specificity of the two enzymes was statistically significant (P0.05). Fecal elastase 1 has a high sensitivity, superior to that of fecal chymotrypsin, in the diagnosis of chronic pancreatitis. For its simplicity and rapidity, it could represent the tubeless test of choice in chronic pancreatitis.

We evaluated a new continuous colorimetric method for serum lipase determination based on the use of a 1,2-diglyceride as substrate and a specific 2-monoglyceride lipase. This test was compared with a turbidimetric assay and also with serum alpha-amylase and pancreatic isoamylase determinations. We studied 32 patients with acute pancreatitis, 27 with chronic pancreatitis in acute painful relapse, 19 with pancreatic cancer, 44 with other digestive diseases, 53 with end-stage renal disease, and 102 healthy controls. The results of the new test were closely correlated with those of the turbidimetric method (r = 0.96). Sensitivity of the new method was elevated (100%): it was the same as that of the turbidimetric method, but slightly higher than that of alpha-amylase and pancreatic isoamylase determinations (93.7 and 96.9%, respectively). Specificity was 95.5%, i.e. higher than that observed using the other tests (86.4, 84.1 and 88.6% for lipase turbidimetric assay, amylase, and pancreatic isoamylase determinations, respectively). The results demonstrate that this new lipase assay is a sensitive, specific test for the diagnosis of acute pancreatitis.

The clinical validity of a continuous colorimetric method for measuring pancreatic lipase was assessed. 1,2-Diacylglycerol containing long-chain fatty acid residues was used as substrate, and the method was adapted to a discrete analyser. The dynamic range was ascertained up to at least 30-fold the upper reference limit. Precision tests on three control sera yielded overall CVs of 4.6% (mean value 21 U/l), 2.4% (115 U/l), and 1.0% (386 U/l), respectively. Using serum samples from normal subjects and patients with pancreatic and non-pancreatic disorders, the present method was compared with a turbidimetric method (r = 0.997; n = 281) and a homogeneous enzyme immunoassay (r = 0.987; n = 93). The reference interval established on 121 healthy subjects was 8-57 U/l (central 95th percentile, median 22 U/l). The sensitivity of this lipase assay in the diagnosis of acute pancreatitis (100%, median 5.6-fold the upper reference limit) was equal to that of the pancreatic isoamylase assay, and higher than that of the total alpha-amylase assay (88.2%); the specificity for acute pancreatitis with respect to a group of patients with acute and chronic non-pancreatic abdominal diseases (91%) was higher than that of both pancreatic isoamylase (76%) and total alpha-amylase (71%).

Serum amylase, pancreatic isoamylase, lipase, trypsinogen and elastase-1 were measured in 100 consecutive patients who were emergency admissions to a surgical department, and in 27 selected patients with proven acute pancreatitis who served as controls. The final diagnoses in the 100 patients of the study group were: acute pancreatitis in eight patients, other digestive diseases in 87, and urogenital tract diseases in five. In the control group, pancreas-specific enzymes were abnormally high in all patients and amylase in 26 out of 27. In the study group, all enzymes were markedly high in all eight patients with acute pancreatitis. In the remaining 92 patients, serum amylase was abnormally high in seven, and at least one pancreatic enzyme was elevated in 16. These elevations were generally mild. The diagnostic efficiency, i.e., the percentage of patients correctly classified, was 96% for pancreatic isoamylase and lipase, 93% for amylase, 91% for elastase-1, and 84% for trypsinogen. We conclude that serum lipase turbidimetric assay is the most suitable test for emergency diagnosis of acute pancreatitis, because it is highly sensitive and specific and simply and quickly performed.

A method has recently been developed for measuring serum pancreatic (P) isoamylase, using two monoclonal antibodies specific for salivary isoamylase. We performed this test on 67 healthy controls and 133 patients: 15 with acute pancreatitis, 53 with chronic pancreatitis (20 during painful relapse and 33 in clinical remission), 18 with pancreatic cancer, 41 with nonpancreatic disease with abdominal pain, five with macroamylasemia, and one with total pancreatectomy. Results were compared with those of a wheat germ inhibition method and with electrophoresis on cellulose acetate. A close correlation was found between the results of immunoinhibition assay and those of the other two tests. All patients with acute pancreatitis had abnormally high values in all three tests. In the group with chronic pancreatitis studied during painful relapse, 16 had an increase in P-isoamylase, as determined with the immunoinhibition assay, 13 with the wheat germ inhibition test, and 15 with electrophoresis. In the group with chronic pancreatitis in clinical remission, we found low values in one patient, by immunoinhibition assay, but found low values in 17 and 19 patients by wheat germ inhibition and electrophoresis, respectively. Low P-isoamylase values corresponded to a severe exocrine pancreatic insufficiency. In the group with pancreatic cancer, the three tests showed similar results, and the majority of the patients had normal values. In the patients with nonpancreatic diseases, abnormally high levels were found in five, by immunoassay, in four by electrophoresis, and in three by the wheat germ inhibition method. In the five cases with macroamylasemia, both inhibition assays erroneously demonstrated an abnormal P-isoamylase elevation. The results show that the three tests are equally useful for the diagnosis of acute pancreatitis, or chronic pancreatitis during an acute relapse. In these diseases, the immunoinhibition test would be the preferred assay because it is simple and rapidly performed.

Fasting serum gastrin and gastrin response to a protein meal were measured in a group of patients with chronic pancreatitis and in controls. No significant differences were found between the two groups of subjects. In patients with chronic pancreatitis no relation was found between gastrin release and the severity of pancreatic exocrine insufficiency.

Serum levels of amylase, pancreatic isoamylase, lipase, trypsinogen, and elastase 1 were determined in 41 patients with pancreatic carcinoma and compared with those 71 patients with chronic pancreatitis and 17 patients with digestive non-pancreatic carcinoma, in an attempt to evaluate their relative values in the diagnosis of pancreatic cancer. Trypsinogen and elastase 1 levels were the most frequently abnormal (56%), followed by pancreatic isoamylase (39%), lipase (34%), and amylase (27%). In 4 patients with resectable cancer levels of all serum enzymes were within normal limits, with the single exception of a low trypsinogen level in one patient. No significant differences in the behavior of serum enzymes were found between patients with pancreatic cancer and those with chronic pancreatitis or digestive non-pancreatic cancer. The results of our study indicate that measurement of serum pancreatic enzymes is of limited usefulness in the diagnosis of pancreatic cancer.

The secretion of bicarbonate, lipase, and chymotrypsin into the duodenum in response to exogenous stimulation with secretin, 1 CU/kg-h, plus caerulein, 100 ng/kg-h, was investigated in 12 patients, on an average, 20.7 months after total gastrectomy and in 14 control subjects. The secretion of bicarbonate and lipase was significantly lower in patients than in controls. The reduction in outputs compared with the control values was 47.9%, 38.7%, and 24.2% respectively for bicarbonate, lipase, and chymotrypsin. Eight of the 12 patients (67%) had steatorrhoea. No significant correlation was found between this parameter and lipase output. It is concluded that the exocrine pancreatic function is impaired in the majority of patients subjected to total gastrectomy. The impairment, which particularly affects bicarbonate and lipase, is generally mild to moderate.

Pancreolauryl test (PLT), a tubeless pancreatic function test, was performed in 40 consecutive patients suffering from chronic pancreatitis, in 21 patients with miscellaneous digestive diseases, and in 18 control subjects to assess its diagnostic sensitivity and specificity. N-benzoyl-L-tyrosyl-p-aminobenzoic acid test (PABA test) and secretin-cerulein test were also carried out to compare the diagnostic value of PLT with that of these two pancreatic function tests. PLT was abnormal in 22 of 40 patients with chronic pancreatitis (55%). In particular, pathological results were found in all patients with severe pancreatic insufficiency and only in four of 14 patients with mild to moderate insufficiency. PABA test showed a slightly lower sensitivity in severe insufficiency, and the same sensitivity in mild-moderate insufficiency. PLT was normal in all control subjects and in 17 of 21 patients with nonpancreatic digestive diseases. Its specificity (90%) was slightly higher than that of PABA test (82%). The results indicate that PLT may be used to support a diagnosis of severe pancreatic exocrine insufficiency, while in mild or moderate insufficiency its diagnostic value is limited.

Serum trypsin-like immunoreactivity (TLI) was studied in 31 patients before and after endoscopic retrograde cholangiopancreatography. None of the patients developed clinical acute pancreatitis. Generally, the serum TLI peak was observed within the first 6 hours after the examination. Most patients (73%) showed a pathologically high TLI but very high values were not frequent (19%). Successful pancreatic opacification was followed by a significant increase in serum TLI which was pathologically high in nearly all cases (18/20). On the contrary, after cholangiography alone abnormal values were less frequent (4/8) and the increase was not significant. In most patients TLI and amylase responses were in agreement. A significant, though poor, linear relation was found between serum TLI and serum amylase 3, 6 and 12 hours after the examination.

We have measured serum immunoreactive pancreatic elastase 1 concentrations in 90 patients with pancreatic cancer in order to determine its usefulness in the diagnosis of this tumor. Abnormal elastase 1 concentrations were found in only 58 (64.4%) of the 90 patients. Fifty (55.5%) had abnormally high values, and eight (8.9%) had abnormally low values. No significant differences in elastase 1 levels were observed between patients with resectable cancer (n = 15) and those with unresectable cancer (n = 75). Moreover, no significant differences were found between elastase 1 concentrations of patients with pancreatic cancer and those of 71 patients with chronic pancreatitis. We conclude that serum elastase 1 measurement does not represent a significant advance in the diagnosis, whether early or late, of pancreatic cancer.

Phosphorylcholine and homocysteine have an important choleretic action and also potentiate exocrine pancreatic secretion by way of stimulation and a more effective preparation of the substrate against attack by lipolytic enzymes. The protection offered by pancreatic enzymes in the correction of the digestive insufficiency in the endoluminal stage is also known. An analysis was therefore made of the action of an association of phosphorylcholine homocysteine and digestive enzymes in cases of exocrine pancreatic insufficiency and primary or secondary malabsorption. This action was evaluated on the basis of the reduction of elimination of steatorrhoea. For this purpose, faecal lipids were determined with the method proposed by van de Kramer et al. The most significant results were obtained in cases where digestive insufficiency was most marked, where correction of the pancreatic enzyme deficiency and improved biliary function were particularly required.

Serum trypsin levels and exocrine pancreatic function were determined in twenty patients with chronic pancreatitis. Very low values of serum trypsin were found in patients with severe pancreatic insufficiency. In patients with mild or moderate pancreatic insufficiency serum trypsin levels were in the normal range.

Item does not contain fulltext In MEG experiments an electromagnetic field is measured at a very high temporal resolution in many sensors located in a helmet-shaped dewar, producing a very large dataset. Filtering techniques are commonly used to reduce the noise in the data. In this paper, spatiotemporal smoothing across space and time simultaneously is used, not simply as a pre-processing step, but as the central focus of a modelling technique intended to estimate the structure of the spatial and temporal response to stimulus. A particular advantage of this approach is the ability to study responses from individual replicates, rather than averages. The benefits of this form of smoothing are discussed and simulation used to evaluate its performance. The methods are illustrated on an application with real data. 10 p.

The analysis of large data sets of standardized mortality ratios (SMRs), obtained by collecting observed and expected disease counts in a map of contiguous regions, is a first step in descriptive epidemiology to detect potential environmental risk factors. A common situation arises when counts are collected in small areas, that is, where the expected count is very low, and disease risks underlying the map are spatially correlated. Traditional p-value-based methods, which control the false discovery rate (FDR) by means of Poisson p-values, might achieve small sensitivity in identifying risk in small areas. This problem is the focus of the present work, where a Bayesian approach which performs a test to evaluate the null hypothesis of no risk over each SMR and controls the posterior FDR is proposed. A Bayesian hierarchical model including spatial random effects to allow for extra-Poisson variability is implemented providing estimates of the posterior probabilities that the null hypothesis of absence of risk is true. By means of such posterior probabilities, an estimate of the posterior FDR conditional on the data can be computed. A conservative estimation is needed to achieve the control which is checked by simulation. The availability of this estimate allows the practitioner to determine nonarbitrary FDR-based selection rules to identify high-risk areas according to a preset FDR level. Sensitivity and specificity of FDR-based rules are studied via simulation and a comparison with p-value-based rules is also shown. A real data set is analyzed using rules based on several FDR levels.

Recent multiple testing (see also Multiple comparisons) applications have benefited from the introduction of methodologies based on the false discovery rate (FDR), which has been defined in a seminal paper [1] as the expected value of the ratio of wrongly rejected null hypotheses (false discoveries) over the total rejected null hypotheses (discoveries). Procedures based on the FDR have been increasing in popularity since they offer a more powerful approach than traditional multiple comparison methods [2] in many applications, especially when the number of tests is very high.

In urban studies the situation where an urban area develops in an inefficient manner is generally referred to as urban sprawl. This phenomenon leads to long-term negative effects for the environment, such as soil sealing, pollution and problems related to transport infrastructure. Offcial land use datasets, such as those from the CORINE Land Cover programme, provide a valuable resource to study urban dynamics. In this work we develop models for representing the urban sprawl phenomenon at a large spatial scale, which involves both estimating the proportion of urbanization over space and finding methods to quantify the urban shape.

In urban planning studies on the dynamics of urban growth, urban sprawl is referred to as an inefficient urban development often linked to sparse building over rural areas. Raster maps of urban morphological zones, such as those produced by the CORINE Land Cover programme of the EEA, provide a valuable resource to study spatial heterogeneities within urban patterns.

Magnetoencephalography (MEG) is a non-invasive technique which measures the electromagnetic activity in the brain by recording the magnetic fields outside the head. Data is acquired by sensitive devices embedded in a helmet placed over the human head. The high temporal resolution of MEG (in the order of milliseconds) is optimal for studying the transient magnetic fields associated with the highly dynamic processes of brain activations. The goal is the identification of spatio-temporal components in the signal that correspond to certain cognitive processes that ideally are carefully manipulated in the respective experiment. Several kinds of noise and artifacts can distort the desired signal. Filtering procedures and averaging across many trials, i.e. replicates of the experiment, are methods usually adopted to summarize the data and increase the signal to noise ratio. However, uncertainty of estimates are usually not taken into account. In this work linear smoothing estimation based on a local fitting approach is applied to smooth the data both in time and space, i.e. the helmet surface, in order to reduce sensor noise. Maps depicting the mean response by smoothing out the sensor noise, plus standard errors for the mean, are produced to help in identifying the time and location where a dipole pattern occurs, which indicates activation. Computational issues are successfully addressed by considering the array representation of the data (Currie et al. 2006). The estimator actually realizes a local mean averaging of the data both over time and space by simply pre-multiplying and post-multiplying the data matrix by a smoothing matrix relative to the space and the time dimension respectively. Standard errors are evaluated by considering, at each time slice, the data as arising from a spatial process, and fitting a covariogram model to the residuals. Analogously, an autoregressive model can be fitted to the residual time series at each sensor. Such a method is helpful in order to address the common case where the sensor noise presents a spatial and temporal structure. The availability of standard errors allows a null hypothesis of null activation to be tested, and maps of t-statistics can be provided to highlight the strength of the detected dipole pattern. The methodology carried out allows single-trial analysis as a useful alternative to the usual practice of averaging raw MEG data from many trials, which usually show a great variability both in phase and amplitude. The benefit of applying moothing estimation at the single-trial level, rather than averaging raw data across replicates, was studied via simulation and also shown in real data examples. Building on this, future research might go in two directions. The first is the development of methodologies which adjust for the trial to trial variability and provide a more effective method of constructing a mean response surface. The second is to consider the multilevel structure of the MEG data in an attempt to model the response by including in the fitting process the variability at the different levels of the hierarchy generated by the experiment (subjects, conditions, trials).

Nonlinear models have been fitted to MEG data in order to improve understanding of brain activity prior to exposure to a stimulus. Such models can be used to characterise brain activity using only a few parameters in order to study within and between subject variability. This knowledge will help to inform estimation of temporal and spatial locations of brain activation in response to a particular stimulus.

Magnetoencephalography (MEG) is a non-invasive technique to measure the neuronal activity in the brain. An electromagnetic eld is measured at a very high temporal resolution in many sensors located in a helmet-shaped dewar producing a very large dataset. In this paper spatiotemporal smoothing is applied in order to identify spatial and temporal patterns and to build a gradient estimator helpful in suggesting the locations of the current dipoles in the brain. Results when applying these tools to a MEG experiment are shown.