Biomedical subjects
Publications and source records attributed to P Pascual.
A rare case of ganglioneuromatous polyposis of the colon found in association with mucinous adenocarcinoma and primary hyperparathyroidism caused by a parathyroid adenoma in a 77-year-old woman is described. We discuss the clinical implications of this finding and review the literature.
OBJECTIVE: To analyze the use of self-expanding metal coated esophageal stents a palliative therapy of malignant dysphagia. METHOD: We performed a one year prospective study placing 12 stents in 10 patients with malignant dysphagia. RESULTS: The insertion mean time was lower than 25 min, and most of our patients (70%) reported a good tolerance. Dysphagia score improved immediately and it lasted until death with no occlusions. Complications appeared early, 17% at the time of placement, with one patient having a life-threatening complication. The probability for these patients not to develop any complications after the three first weeks will be about 60%. CONCLUSIONS: Self-expanding metal coated esophageal stents provide a fast and lasting relief in malignant dysphagia, with a good tolerance.
Explore the source record for details and available documents.
Enterococcus avium has rarely been reported as a pathogen in humans. We describe a case of endocarditis caused by E. avium. It responded to ampicillin and gentamicin, although a valve replacement was necessary for severe aortic insufficiency. This microorganism should be regarded as significant in endocarditis.
The different preparative techniques and related analytical methods used for purification of glutathione peroxidase, glutathione transferase and glutathione reductase, described in papers published in the last ten years, have been reviewed in this article. Among the different purification techniques, chromatography has played a relevant role, being reported in all the papers reviewed, whereas other preparative techniques such as electrophoresis and isoelectric focusing were less employed and have been reported in only ca. 3% of cases. Frequently, several different chromatographic modes and several rechromatography steps have been employed. The use of at least three different chromatographic modes has been reported in 53% of total reviewed papers, whereas 41% of them employed two differents modes and in only 6% a single preparative chromatographic step was used. To evaluate losses and improve recovery, analytical methods for quantitation of protein and assay of enzymatic activity must be used in each purification step. Among these analytical techniques, gel electrophoresis, under denaturing conditions, has been widely used to assess purity of enzyme preparation. A discussion of the different activity assay methods used for these three enzymes is also presented in this article.
Increased activities of several detoxifying and antioxidant enzymes were detected in mollusc and fish from Spanish littoral areas with high metal contents. Ethanolic extracts from molluscs contained direct-acting and polar genotoxins of oxidative type, which were detected by strain TA102 of S. typhimurium and catalase-deficient strains of E. coli. Animals from contaminated sites contained less genotoxins than those from control areas. Polluted fishes displayed highly induced cytochrome P-450 activity and increased promutagen activation capabilities. In addition, specific forms of glutathione transferase and superoxide dismutase were induced, particularly highly acidic forms.
A fast, sensitive and direct method has been developed for the determination of glutathione peroxidase activity (both selenium- and non-selenium-dependent) in cell-free preparations. The assay is based on the separation and quantitation of reduced and oxidized glutathione by capillary electrophoresis. The electrophoretic separation buffer was 100 mM sodium tetraborate (pH 8.2) containing 100 mM sodium dodecylsulphate. A micellar electrokinetic mechanism took place under these conditions, and a total mass recovery was observed for both peptides. The reproducibility of migration times was excellent (less than 3% variability). A linear detector response range was observed in the range 5-50 U/ml, and both the reproducibility and accuracy were satisfied. Samples out of this linear range could be analysed by either increasing the reaction time or diluting the enzyme preparation. The results obtained with the new direct capillary electrophoresis assay were compared with those derived from a reversed phase high-performance liquid chromatographic and spectrophotometric coupled assay. A very good agreement was found between the two direct assay methods in all samples. Capillary electrophoresis is a versatile technique that allows the automation of the glutathione peroxidase assay in a reproducible manner and within a relatively short time with sufficient accuracy and precision.
The analysis of glutathione transferase (GST) isoenzyme patterns is of interest in many fields as hepatic glutathione transferase activity is increased by exposure to a variety of xenobiotics and its isoenzymatic forms are induced differentially. A high-performance liquid chromatography method has been developed for the rapid determination of individual isoenzyme levels in crude extracts using an anion-exchange column connected to an on-line system to automatically detect GST activity with 1-chloro-2,4-dinitrobenzene as the substrate. When 50-200 microliters of a cytosolic fraction of fish liver containing up to 15 mg/ml of protein and less than 2 units of GST were injected, a high resolution and highly reproducible chromatogram was obtained. The activity profile determined automatically showed eight to twelve peaks (depending on the sample) that were quantified and could be classified into three groups. Starting from intact tissue, a complete isoenzyme pattern could be obtained in less than 3 h. The method has been applied to ecotoxicological studies with fish samples.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A patient with infantile onset methylmalonic aciduria and homocystinuria (Cbl-C mutant) is described. Therapy with hydroxycobalamin, folate and vitamin B6 improved his condition. As hypomethioninaemia and homocystinaemia persisted, he was treated with intramuscular methylcobalamin, but without success. Treatment with betaine started at 25 months of age, normalized plasma methionine and elicited disappearance of homocystinaemia. Results of biochemical studies in cultured fibroblasts paralleled those described for other Cbl-C patients except that methylmalonyl-coenzyme A mutase activity in disrupted fibroblasts was in the normal range.
Explore the source record for details and available documents.
Methodological difficulties met in acupuncture cannot be overcome without epistemological analysis by researchers and practitioners. This is because of the 'cognitivo-cultural' gap between Occidental and Chinese traditions. With this aim, the author considers the role of cognitive expectancies in the effect of antalgic acupuncture, and draws epistemological then methodological conclusions. After comparing the advent of the holistic movement with the crisis of rationalism in medicine, an attempt is made to formulate an evaluation of the problems in acupuncture in terms of metaphysical realism. The author challenges the holistic model compared to the orthodox bio-medical model.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.