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A Obrador

Publications and source records attributed to A Obrador.

At least 19 recordsLinked to original sources
PubMed2006

Review article: colorectal cancer surveillance in ulcerative colitis - what should we be doing?

Different societies have published guidelines for colorectal cancer (CRC) surveillance in ulcerative colitis (UC). While it would seem that most gastroenterologists and endoscopists agree with these guidelines, different studies have shown that in clinical practice, the concept of dysplasia is not fully understood, and therefore, the guidelines are not always followed. According to some studies, the reason why gastroenterologists do not follow the recommendations is inadequate education. The main advance in recent years in this subject is in endoscopic diagnosis of dysplasia. The magnification and chromoendoscopy allow targeted biopsies to be taken. Some studies indicate that nontargeted biopsies are not useful in ruling out dysplasia. It is also important to realize that most dysplasia is visible in conventional colonoscopy. In colonoscopy, it is not only significant to detect dysplasia-associated lesions or masses; the endoscopist should also be trained to detect, in the course of conventional exploration, subtle changes in colour or in mucosal surfaces that imply dysplasia. Adherence to guidelines had been extensively assessed in other disease conditions (asthma, hypertension, etc.). According to our knowledge there are no such data regarding CRC surveillance in UC. Some barriers that may affect physicians include: (i) knowledge (lack of awareness or lack of familiarity); (ii) attitudes (lack of agreement, lack of self-efficacy, lack of outcome expectancy, or the inertia of previous practice) and (iii) behaviour (external barriers). In conclusion, we need new guidelines for CRC surveillance in UC, which must take into account the advances in risk factors of dysplasia and new technologies to study colon dysplasia.

Clinical Competence↗
PubMed2006

Prevalence of HFE C282Y and H63D in Jewish populations and clinical implications of H63D homozygosity.

The frequencies of C282Y and H63D mutations of the HFE gene vary between different populations. A previous study showed an unexpectedly high H63D frequency in Chuetas (a population of Jewish descent). The present study addressed the question of the distribution of these mutations in Jewish populations from different origins and studied the possible causes of the high H63D frequency in Chuetas. Moreover, to improve the understanding of the controversial relationship between H63D homozygosity and iron overload, a group of patients with altered iron metabolism were studied. The high frequency of H63D mutation in Chuetas is not due to a high prevalence of this mutation in Sephardic Jews. Jewish populations have low C282Y and moderate H63D frequencies, suggesting slight gene flow from their surrounding populations. In accordance with historical and demographic data, genetic drift is the most probable cause for the singular H63D frequency in Chuetas. Clinically, this study of H63D homozygotes supports the conclusion that this genotype must be taken into account, because it confers an increased risk of iron overload and therefore genetic susceptibility to developing hereditary hemochromatosis or to aggravating other diseases.

Alleles↗
PubMed2006

[Implantation of a hospital registry of hereditary nonpolyposis colorectal cancer].

INTRODUCTION: Identification of patients with hereditary nonpolyposis colorectal cancer (HNPCC) can allow colorectal cancer (CRC) prevention through colonoscopy and polypectomies. The purpose of this study was to report the clinical characteristics of HNPCC families in our registry. PATIENTS AND METHOD: HNPCC was identified using the Amsterdam criteria. Familial clustering of CRC and extracolonic cancers were investigated in families. Individuals at risk were offered annual colonoscopy, starting from the age of 25 years. RESULTS: Twelve HNPCC families were identified. There were 46 cases of CRC in 38 patients. The mean age at diagnosis of CRC was 45.4 +/- 12.7 years (range 25-73 years). In patients with documented disease, right-sided tumors predominated. Eleven patients with extracolonic cancer were identified (six tumors located in the endometrium). Of 43 at-risk individuals, 29 accepted surveillance. CONCLUSIONS: Our data confirm the importance of the family history in identifying HNPCC. This study confirms previously described characteristics in HNPCC, namely, early age at onset of CRC, right-sided predominance, multiple synchronous and metachronous neoplasms, and increased extracolonic cancers. This is the first study of clinical data in a Spanish HNPCC registry.

Adult↗
PubMed2004

Granulocyteaphaeresis in steroid-dependent inflammatory bowel disease: a prospective, open, pilot study.

BACKGROUND: Uncontrolled studies suggest that granulocyteaphaeresis might be useful in the management of active ulcerative colitis. AIM: To assess the efficacy of granulocyteaphaeresis treatment in active steroid-dependent inflammatory bowel disease. METHODS: We conducted a multicentre, prospective, open, pilot study in patients with steroid-dependent inflammatory bowel disease. All patients were started on 60 mg/day of prednisone; after 1 week, a five-session programme of granulocyteaphaeresis (once per week) was started. The steroid dose was tapered weekly if there was clinical improvement. Remission was defined as an inactive clinical activity index together with complete withdrawal of steroids at week 6. The patients were followed up for at least 6 months or until disease relapse. RESULTS: Twenty-six patients (14 ulcerative colitis, 12 Crohn's disease) were included. More than a half had been previously treated with immunomodulators. Remission was achieved in 62 and 70% of ulcerative colitis and Crohn's disease, respectively. During a median follow-up of 12.6 months, six of eight ulcerative colitis patients maintained their clinical remission; however, only one Crohn's disease patient remained in remission after the first 6 months of follow-up. CONCLUSIONS: Granulocyteaphaeresis is a safe treatment option in inflammatory bowel disease. A five-session programme of granulocyteaphaeresis seems to be efficient in the treatment of steroid-dependent ulcerative colitis, but not in Crohn's disease.

Adult↗
PubMed2003

[Lactose malabsorption in ulcerative colitis. A case-control study].

BACKGROUND: The role of lactose malabsorption in ulcerative colitis is controversial. The aim of this study was to compare the prevalence of lactose malabsorption in a group of ulcerative colitis patients and a control group and to modify lactose consumption in view of the results. METHODS: Lactose malabsorption was studied using the hydrogen breath test in 52 patients with ulcerative colitis and 34 controls after ingestion of 25 g of lactose. A questionnaire on ingestion of milk products was also administered. RESULTS: Of the 52 patients with ulcerative colitis, 13 (25%) presented lactose malabsorption compared with 11 of the 34 (32%) controls (p = 0.45). Twenty-four patients (46%) had been advised to completely eliminate lactose from their diets. Twenty-seven of the 39 patients without malabsorption had reduced or eliminated lactose consumption after being diagnosed with ulcerative colitis. CONCLUSIONS: No significant differences in the prevalence of lactose malabsorption was found between patients with ulcerative colitis and controls. We believe that systematic elimination of lactose from the diets of these patients is erroneous. In our environment, we recommend the hydrogen breath test only in patients with symptoms of lactose intolerance.

Adolescent↗
PubMed2002

Zinc transformations in acidic soil and zinc efficiency on maize by adding six organic zinc complexes.

Experiments under laboratory and greenhouse conditions were conducted to study the response of maize (Zea mays L.) to Zn fertilizer applications (Zn-phenolate, Zn-EDDHA, Zn-EDTA, Zn-lignosulfonate, Zn-polyflavonoid, and Zn-heptagluconate) in an Aquic Haploxeralf soil. The application of Zn complexes significantly increased Zn uptake by the plant compared with that in the control soil. The highest enhancements were obtained in soil treated with Zn-EDTA, Zn-lignosulfonate, and Zn-EDDHA. The highest percentages of Zn taken up by the plants occurred when 20 mg x kg(-1) Zn was applied as Zn-EDTA fertilizer and 10 mg x kg(-1) as Zn-lignosulfonate fertilizer. In the greenhouse experiment, Zn speciation in soil after harvesting showed that almost all Zn was found in the residual fraction followed by metal in the water-soluble plus exchangeable fraction and metal bound to organic matter. The most effective fertilizers maintaining Zn in the most labile fractions were Zn-phenolate, Zn-EDTA, and Zn-lignosulfonate. Conversely, in the incubation experiment, only a small percentage of Zn was found in the water-soluble plus exchangeable fraction and no differences in the Zn distribution were observed between the different fertilizer treatments. The micronutrient content in maize was positively correlated with the water-soluble plus exchangeable Zn as well as with the available Zn determined by the diethylenetriaminepentaacetic acid and Mehlich-3 methods, in the greenhouse experiment. Results of this study showed that the incubation experiment in acidic soil is not a suitable tool to establish the different effectiveness of Zn chelates in plants.

Chelating Agents↗
PubMed2002

In hereditary hemochromatosis, red cell apheresis removes excess iron twice as fast as manual whole blood phlebotomy.

The current treatment of hereditary hemochromatosis (HH) consists of performing periodic manual whole blood phlebotomies. Erythroapheresis (EPH) is considered to be an alternative procedure if the classic treatment is contra-indicated. A prospective study of 13 consecutive cases of HH were included in a periodic EPH program with the aim of assessing the efficacy, feasibility, and tolerability of EPH in the treatment of HH by induction and maintenance. Iron depletion (ferritin <20 microg/l) was achieved in all patients after a mean of 6.7 +/- 2.9 months of treatment and a mean of 13.5 +/- 7.2 EPH sessions. The procedure was well tolerated and there were no complications. After a follow-up period of 10.5 +/- 6.6 months, only four patients have required further maintenance sessions beyond 6 months after completing the induction therapy. The efficacy, speed, tolerability, and more favorable schedule of an EPH program facilitate treatment of HH.

Adult↗
PubMed2002

Distribution of HFE C282Y and H63D mutations in the Balearic Islands (NE Spain).

The HFE gene contains two main missense mutations: C282Y and H63D. Individuals with these mutations carry a risk of developing hereditary haemochromatosis (HH). The common form of this disease is due to homozygosity for the C282Y mutation. Population studies have shown the variation of the prevalence of these mutations in different countries and ethnic groups. The purposes of this current study were to determine the prevalence of the C282Y and H63D mutations in the Balearic Islands and the genotypic characterization of patients diagnosed with HH, as well as those with iron overload and liver diseases. A total of 1330 Balearic chromosomes were analyzed. The results showed that the populations of the Balearic Islands were not homogeneous. No C282Y carriers were observed in a group of descendants of Majorcan Jews (Chuetas) and the frequency was very low in Minorca (1.2%) in comparison with the other islands of Majorca (4.7%) and Ibiza (6.5%). The carrier frequency of the H63D mutation was similar in the three islands and very high (43.1%) in the descendants of Majorcan Jews. The study of patients was carried out in 129 individuals. The homozygous C282Y genotype was the principal one involved in hereditary haemochromatosis (90%), whereas the other HH patients were C282Y/H63D compound heterozygous and H63D homozygous.

Adolescent↗