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J Carrascosa

Publications and source records attributed to J Carrascosa.

7 recordsLinked to original sources
PubMed2003

[Virtual Colonoscopy. Experience in 500 patients].

OBJECTIVE: To show our experience and results in Virtual Colonoscopy (VC). MATERIAL AND METHOD: Five hundred patients with personal or familial history of colorectal carcinoma and/or adenomas, or any kind of coloproctologic symptoms were studied. VCs were practiced using a helical CT scanner (300 patients) and a multislice CT scanner (200 patients) a few hours after Conventional Colonoscopy (CC), considered the gold standard. The patients were evaluated in a prospective blind study, to determine sensitivity and specificity of VC. Findings were classified as: 1) normal studies; 2) studies with pathological findings. This one was subdivided into: 2a) Lesions below 5 mm., 2b) Lesions between 5-9 mm., 2c) Lesions above 9 mm. RESULTS: VC detected 253 normal studies whereas CC only detected 233. The sensitivity and specificity for each subgroup were: 2a) 87.8% and 86.9%; 2b) 95.6% and 91.4%; 2c) 100.0% and 100.0% respectively. CONCLUSION: VC is a feasible and useful method for evaluating the entire colon. It is well tolerated, it has no complications and a high sensitivity and specificity for elevated lesions, especially the ones above or equal to 5 mm.

Adult↗
PubMed2002

[Virtual gastroscopy. Preliminary experience].

OBJECTIVE: To define the role of virtual gastroscopy (VG) in the detection of elevated lesions comparing its results with conventional endoscopy (CE) as the gold standard method. MATERIALS AND METHODS: Between December 2000 and July 2001, 19 patients were evaluated. The age ranged between 41 and 72 (mean 58.8 years old). VG and CE were performed in all the patients during the same week. VG were carried out with a multislice CT scanner (Mx 8000, Marconi Medical Systems). The technical parameters used were 3 mm with slices and 1.5 mm reconstruction intervals. The acquisition time was 22 seconds. Images were sent to a workstation (MxView, Marconi Medical Systems) where they were reprocessed in three different ways: 1) Bidimensionally 2) Tridimensionally 3) Virtual Endoscopy Findings of VG were compared with CE. RESULTS: VG detected 39 lesions, whereas CE detected 40 lesions. There were 39 true-positive findings, 2 true-negative findings, 0 false-positive findings and 1 false-negative findings. The Sensitivity (Se) was 97.5%; Specificity (Sp) was 100%, positive predictive value 100% and Negative predictive value 66%. CONCLUSIONS: VG is a new non-invasive method with high Se and Sp in the detection of elevated lesions. The actual role of VG consist in identification of gastric lesions and possibility to diagnose gastric disease.

Adult↗
PubMed1999

Polymerization of bacteriophage T4 tail sheath protein mutants truncated at the C-termini.

Gene 18 of bacteriophage T4 encodes the contractile protein of the tail sheath. Previous work has shown that the full-length recombinant gene product (gp) 18 of 658 amino acid residues assembles in Escherichia coli cells into a long polysheath structure. However, the gp18 mutants truncated at the N-termini form insoluble aggregates similar to inclusion bodies. In this study, six plasmid vectors expressing the recombinant gp18 proteins truncated at the C-termini have been constructed. The CDelta58, CDelta129, CDelta152, C[g1]72, CDelta248, and CDelta287 proteins contain 600, 529, 506, 486, 410, and 371 residues of the full-length gp18 molecule, respectively. All the recombinant proteins were soluble and, except for the CDelta287 mutant, were assembled into polysheath-related structures. Electron microscopy of negatively stained purified proteins was performed and the resulting images were analyzed by computing their Fourier transforms. The CDelta58 and CDelta129 mutants, in addition to forming common contracted-type polysheath structures, assembled into thinner filaments that we called "noncontracted polysheaths" (NCP). The CDelta152, CDelta172, and CDelta248 proteins assembled into the NCP type only. Image processing showed that the NCP filaments significantly differ from both extended sheaths of T4 particle and polysheaths. The structure of the NCP filaments might correspond to the transitional helices postulated by Moody (J. Mol. Biol., 1973, 80, 613-636) that appeared during the process of tail contraction. Our results suggest that a short region at the C-terminus of the CDelta129 protein determines the contractile properties of the gp18 molecule. The shortest, the CDelta287 protein, does not assemble into regular structures, thus indicating that a sequence's stretch at the C-end of the CDelta248 mutant might be responsible for polymerization of gp18.

Amino Acid Sequence↗
PubMed1992

Subcellular distribution of GLUT 4 in the skeletal muscle of lean type 2 (non-insulin-dependent) diabetic patients in the basal state.

Insulin resistance of the skeletal muscle is a key feature of Type 2 (non-insulin-dependent) diabetes mellitus. To determine whether a decrease of glucose carrier proteins or an altered subcellular distribution of glucose transporters might contribute to the pathogenesis of the insulin resistant state, we measured glucose transporter numbers in membrane fractions of gastrocnemius muscle of 14 Type 2 diabetic patients and 16 non-diabetic control subjects under basal conditions. Cytochalasin-B binding and immunoblotting with antibodies against transporter-subtypes GLUT 1 and GLUT 4 were applied. The cytochalasin-B binding values (pmol binding sites/g muscle) found in a plasma membrane enriched fraction, high and low density membranes of both groups (diabetic patients and non-diabetic control subjects) suggested a reduced number of glucose transporters in the plasma membranes of the diabetic patients compared to the control subjects (diabetic patients: 1.47 +/- 1.01, control subjects: 3.61 +/- 2.29, p less than or equal to 0.003). There was no clear difference in cytochalasin-B binding sites in high and low density membranes of both groups (diabetic patients: high density membranes 3.76 +/- 1.82, low density membranes: 1.67 +/- 0.81; control subjects: high density membranes 5.09 +/- 1.68, low density membranes 1.45 +/- 0.90). By Western blotting analysis we determined the distribution of the glucose transporter subtypes GLUT 1 and GLUT 4 in the plasma membrane enriched fraction and low density membranes of seven patients of each group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1983

[Critical evaluation of echography in the diagnosis of cholestatic jaundice].

Seventy one patients affected by cholestasis and jaundice were studied by means of ultrasound between september 1980 and february 1983 in order to evaluate the accuracy of this procedure in the investigation of the site of obstruction and its ethiology. The ultrasound findings were correlated with those obtained by opacification of the bile ducts, either endoscopic or percutaneous, and by surgery. The sonographic diagnosis of cholestatic jaundice was based on the size of the biliary tract taking in account that the intrahepatic branches are not evident in normal conditions and considering 4-5 mm and 7-8 mm as the upper limits for the proximal and distal segments of the common bile duct respectively. The accuracy of ultrasound in establishing the common bile duct size was 98%. Forty eight patients had extrahepatic obstruction, 45 of whom had a dilated common bile duct (94%), while 3 were normal (6%). Twenty two patients had an intrahepatic cholestasis, 20 of whom had a normal size of the common bile duct (91%) while 2 showed a dilatation (9%). Thus, the sensitivity was 95.7% and the specificity 86.9%. The ethiologic diagnosis was available in 31 patients with extrahepatic obstruction (65%) and in 7 with intrahepatic cholestasis (32%). Dilated common bile duct with stones and pancreas and gallbladder carcinoma were the most common causes of obstructions we have found in this group of patients. In patients with cholestasis and jaundice the ultrasonic diagnosis should establish the site of obstruction and, if it is possible, the ethiology.

Adult↗
PubMedDate not supplied

Multislice CT virtual angioscopy of the abdomen.

BACKGROUND: Computed tomographic (CT) angiography represents an important clinical tool in the evaluation of vascular disorders. Virtual angioscopy can be reconstructed with volumetric CT data sets. We evaluated the feasibility and clinical value of this application in the assessment of abdominal vessels. METHODS: Data sets of CT angiographic studies obtained with helical (n = 120) and multislice (n = 180) CT scanners were analyzed on a workstation for postprocessing. Vascular evaluation was done on conventional enhanced axial images, three-dimensional reconstructions, and virtual angioscopic images. RESULTS: We made 123 studies in patients without aortic disease. Of the patients evaluated for stent-graft treatment, 63 showed normal patency, seven had partial thrombosis of the stent-graft, five showed total occlusion of the stent-graft, and 10 had leaks. From the 92 remaining CT studies, 63 vascular aneurysms and nine dissections were diagnosed. CONCLUSION: The current technology produces high-quality virtual angioscopic images. Although axial and multiplanar views are usually adequate for detecting a vascular disorder, virtual angioscopic views better define anatomic details.

Abdomen↗