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R Corpas

Publications and source records attributed to R Corpas.

5 recordsLinked to original sources
PubMed2006

Insulin resistance as a non-invasive method for the assessment of fibrosis in patients with hepatitis C: a comparative study of biochemical methods.

INTRODUCTION: Insulin resistance (IR) promotes the progression of fibrosis and diminishes response to treatment in patients with hepatitis C. Recently, Sydney's index (includes IR) has been proposed as a non-invasive method for the prediction of fibrosis. OBJECTIVE: To assess the usefulness of Sydney's index for the prediction of advanced fibrosis (F3-F4) or absence of significant fibrosis (F0-F1) in patients with chronic hepatitis C. PATIENTS AND METHODS: We included 131 patients suffering from chronic hepatitis C. Mean age was 40 +/- 11, 78 men and 53 women. Fibrosis stage was (F0-F1) 69 patients, F2: 40, and advanced (F3-F4) in 22 patients. We measured baseline AST, ALT, GGT, platelet, cholesterol, alcohol, and IR (HOMA - IR) levels. Sydney, Forns' and APRI indexes were calculated. RESULTS: The area under the curve for the diagnosis of absence of significant fibrosis in each method was: Sydney: 0.80, Forns: 0.71, APRI: 0.70; p = ns. Moreover, the diagnostic capacity of advanced fibrosis was: Sydney: 0.88, Forns: 0.83, APRI: 0.82; p = ns. The predictive negative value of significant fibrosis was 74, 72, and 67%, respectively. Due to the presence of intermediate values, the indexes were not applicable to 36, 44 and 43% of patients respectively. CONCLUSIONS: The incorporation of insulin resistance among biochemical non-invasive methods slightly improves the yield of other indexes. Nevertheless, results are suboptimal, and more than one third of patients might not be correctly classified.

Adult↗
PubMed2004

[Determination of hepatitis B virus genotype and detection of lamivudine-resistance mutations].

OBJECTIVES: To determine hepatitis B virus (HBV) genotypes in southern Seville (Spain) and investigate the development of lamivudine-resistance mutations by using a hybridization technique with specific probes and by comparing the results with those of the direct sequencing technique. To evaluate the temporal relationship between variations in the level of HBV-DNA and detection of mutant variants. To analyze the influence of several genotypes on the pattern of mutations developed and on values of viral load and alanine aminotransferase (ALT) after their development. PATIENTS AND METHOD: In 37 patients with chronic HBV infection, HBV genotype was determined using the LiPA technique. In 10 of these patients undergoing lamivudine treatment for a mean of 19.2 months, the development of lamivudine-resistant mutations was investigated. In these 10 patients, the LiPA technique was compared with direct sequencing. During lamivudine treatment, we determined HBV-DNA by polymerase chain reaction (PCR) and ALT every 3-6 months. RESULTS: The most frequent genotypes were D (45.9%) and A (18.9%); 2 patients were genotype B while 18.9% had mixed genotypes. Sequencing showed identical results except in one mixed genotype. Mutations were found in 60% of the cases. The results of sequencing were in agreement, except in the detection of mixed populations composed of mutants and wild-type (WT). Patients with genotype A showed the pattern M204I+WT in the first 12 months and those with genotype D showed the pattern L180M+M204V with or without WT at 18 months. In 5/6 cases, an increase of > 1 log10 in HBV-DNA was observed 3-8 months before the mutation was detected by LiPA. In patients with genotype B, levels of HBV-DNA and ALT after the development of mutations was lower than basal levels and was also lower than those in patients with genotypes A and D. CONCLUSIONS: The LiPA technique for determination of HBV genotype and detection of lamivudine-resistance mutations shows excellent correlation with the most complex sequencing technique. Genotype D predominates in southern Seville. During lamivudine treatment, an increase in the level of HBV-DNA detected by PCR predicts the development of mutations before these are demonstrated by LiPA.

Adult↗
PubMed2001

Processing of crawfish (Procambarus clarkii) for the preparation of carotenoproteins and chitin.

Crawfish carotenoproteins and chitin are obtained by a combined process based on flotation-sedimentation and in situ lactic acid production. The carotenoprotein PF(1) obtained has a high content in essential amino acids, w-3-fatty acids, and carotene (mainly astaxanthin) and constitutes an excellent nutritional source for patients with malnutrition. The carotenoprotein PF(2) has a lower nutritional quality but with a substantial carotene content can be used as a feed for animals where coloration is required, such as salmon and trout bred under aquaculture. Chemical and spectrometric (FTIR and (13)C NMR) characterization shows the obtained chitin to be of high quality, similar to that available commercially, for medical and nutritional uses.

Animals↗
PubMed2000

Brain mitochondrial complex I inactivation by oxidative modification.

In vitro oxidation of the brain mitochondrial complex I by the hydroxyl radical generating system ascorbate/Fe(III)/O(2) has been carried out. Complex I inactivation, by oxidation, has been studied using a method based on the resolution of proteins by blue native polyacrylamide gel electrophoresis (BN-PAGE), followed by total protein quantification by staining with Coomassie brilliant blue, in-gel activity quantification, and quantification of oxidized proteins by labelling with DIG-hydrazide and immunodetection with an anti-DIG-AP. Quantification was carried out by densitometry procedure. Our results show that oxidation is a continuous process, increasing rapidly at the beginning, reaching a plateau after 8 h of incubation. There is practically no inactivation until a threshold value of damage is reached. Below this, the complex activity is resistant to the aggression of oxygen-reactive substances and free radicals, but once the threshold value is passed, activity is lost rapidly.

Animals↗