Facultad de Ciencias geológicas

Objective To determine the association between the self-report of pain and disability and findings on lumbar MR images, and to compare two different health care providers in Spanish patients with low back pain (LBP). Design Cross-sectional Material and methods A total of 278 patients, 137 men and 141 women aged 44±14 years submitted with low back pain (LBP) were studied. One hundred and nine patients were from the National Health System (NHS) and 169 from private practice. Patients with previous discitis, surgery, neoplasm or traumatic episodes were excluded. Every patient completed a disability questionnaire with six core items, providing a score of disability from 2 to 28. All patients had sagittal spin-echo T1 and turbo spin-echo T2, axial proton-density and MR myelography weighted images. MR images of the two most affected disc levels were read, offering an MR imaging score from 0 to 30. Results Patients with a combination of LBP and sciatica showed the highest levels of disability (p=0.002). MR imaging scores only correlated with pain interference with normal work (p=0.04), but not with other disability questions. Patients from the NHS showed greater disability scores than private ones (p=0.001) and higher MR imaging scores (p=0.01). Conclusion In patients with LBP, MR imaging only correlates with pain interference with work but not with other disability questions. Differences are found between private and NHS patients, the latter being more physically affected.

The study was aimed at determining the association between the self-report of pain and disability by means of Northwick neck pain questionnaire (NPQ) and cervical spine MR imaging findings. A random sample of 251 patients, 132 men and 119 women aged 43±13 years, submitted with neck pain were investigated. Patients with previous discitis, surgery, neoplasm or hospitalized for cervical spine trauma were excluded. All patients completed the NPQ and were studied with sagittal gradient-echo T1 and turbo spin-echo T2, axial gradient-echo T2* and heavily T2 weighted MR myelographic weighted images. MR images of the two most affected disc levels were read, offering an MR imaging score from 0 to 30. There was no statistically significant correlation between NPQ and MR imaging scores. From the NPQ items, only difficulty in sleeping and numbness were related to the MR imaging score. Disc extrusion was the only MR finding almost significantly associated with NPQ (P=0.054). Neck injury did not increase NPQ scores. In patients with neck pain, NPQ scores do not correlate with MR imaging findings. NPQ and cervical spine MR imaging show different facets of the multidimensional complex of neck pain.

We have used the leave-one-out (LOO) method and the area under the receiver operating characteristic (ROC) curve to validate logistic models with a sample of 167 patients with calvarial lesions. Seven logistic regression models were developed from 12 clinical and radiological variables to predict the most common diagnoses separately. The LOO method was used to test the validity of the equations. The discriminant power of every model was assessed by means of the area under the ROC curve (A z ). The model with the greatest discrimination ability for the whole data set was the osteoma equation (A z ϭ 0.951). The discriminatory ability of the statistical models decreased significantly with the LOO procedure, having the malignancy model the highest value (A z ϭ 0.931). The LOO method can obtain a high benefit from small samples in order to validate prediction rules. In studies with small samples, resampling techniques such as the LOO should be routinely used in predictive modeling. This method may improve the forecast of infrequent diseases, such as calvarial lesions. J CLIN EPIDEMIOL 52;3:237-241, 1999.

To study the possible association between chronic pancreatitis (CP) and liver cirrhosis (LC) of alcoholic etiology, after excluding any other causes. METHODS: One hundred and forty consecutive alcoholic patients were subdivided into three groups: CP (n = 53), LC (n = 57), and asymptomatic alcoholic (n = 30). Clinical, biochemical and morphological characteristics, Child-Pugh index, indocyanine green test, and fecal pancreatic elastase-1 test were assessed. RESULTS: In patients with cirrhosis, major clinical manifestations of CP such as pancreatic pain and steatorrhea, as well as imaging alterations of CP such as calcifications, duct dilation and pseudocysts were absent; insulin-dependent diabetes was present in 5.3% of cases, and elastase-1 test was altered in only 7%, and severely altered in none. In patients with CP, clinical characteristics of cirrhosis such as ascites, encephalopathy and gastrointestinal hemorrhage were present in one case, Child-Pugh grade > A in 5.7%, and altered indocyanine green test in 1.9% cases. In asymptomatic alcoholism, there was only a non-coincident alteration of elastase-1 test and indocyanine test in 14.8% and 10%, respectively, but other characteristics of cirrhosis or CP were absent. An inverse correlation (r = -0.746) between elastase-1 test and indocyanine test was found in alcoholic patients. CONCLUSION: There is a scarce coincidence in clinical and morphological alterations among patients with CP or LC of alcoholic etiology, but an inverse correlation between pancreatic and liver function tests. These findings support that these alcoholic diseases evolve in a different manner and have different etiopathogenesis. Does an association exist between chronic pancreatitis and liver cirrhosis in alcoholic subjects? World

Background. It has been shown that biochemical laboratory values only are useful parameters in distinguishing gallstone from nongallstone acute pancreatitis. We assessed the diagnostic usefulness of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) for identification of occult microlithiasis in idiopathic acute pancreatitis. Methods. Ninety-one patients with idiopathic acute pancreatitis who underwent microscopic examination of stimulated duodenal bile sediments were retrospectively studied. According to earliness of ALT and AST assay after the onset of abdominal pain, patients were divided into two groups: group A, within the first 24 h (n=56) and group B, between 24 and 72 h (n=35). Results: ALT and AST values expressed as number of elevations of the upper limits of normal were higher in group A patients with positive biliary drainage than in group B. Median (range) ALT and AST values were 2.5 (0.1–18.1) vs 0.4 (0.1–8.6) and 3 (0.3–17.4) vs 0.5 (0.3—11.9), respectively. In the univariate analysis and receiver operating characteristic (ROC) curves, ALT within the first 24 h showed a sensitivity of 73%, specificity of 86%, and positive predictive value of 92% for a cutoff of 1.2 elevations of the upper limit of normal. These values were slightly higher, although without statistically significant differences, than those of AST (73, 80, and 89%, respectively). Conclusion. Serum increases of aminotransferases, especially alanine aminotransferase (ALT), were suggestive of microlithiasis in idiopathic acute pancreatitis, particularly when assessed early after the onset of abdominal pain.

Los lahares son uno de los peligros volcánicos más relevantes, responsables de pérdidas humanas y materiales en todo el mundo. Los métodos existentes para mapear las zonas de peligro de lahar incluyen herramientas de modelado con diferentes enfoques (empírico, físico, probabilístico) y se enfocan en la fase rica en detritos siendo menos versátiles en su aplicación a la fase diluida. Esta última caracteriza la sección frontal del flujo y, aunque es menos destructiva de la infraestructura física, es responsable de la inundación de áreas bajas en los abanicos aluviales, lugar donde habitualmente se encuentran los asentamientos humanos. El volcán Villarrica (Chile), en la Zona Volcánica Andina Sur (33 °-46 ° S), es uno de los volcanes más activos de América del Sur y reconocido como un generador de lahares. En efecto, una caldera anidada en el edificio volcánico alberga un glaciar con potencial de derretirse en erupciones de alta tasa de efusión, con la consiguiente activación de lahare...