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Dive into the research topics where Juan L. Mendoza is active.

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Featured researches published by Juan L. Mendoza.


Digestive Diseases and Sciences | 2002

Myenteric antiplexus antibodies and class II HLA in achalasia.

Antonio Ruiz-de-León; Juan L. Mendoza; Concepción Sevilla-Mantilla; Miguel Fernández Arquero; Julio Pérez-de-la-Serna; Ana Gónzalez Vigo; Enrique Rey; Angeles Figueredo; Manuel Díaz-Rubio; Emilio G. de-la-Concha

Achalasia, a motor disorder of the esophagus, is accompanied by autoimmune phenomena that could be playing a role in the pathogenesis of the disease. Our objective was to establish the genotypic frequency of the HLA-DR and DQ alleles in patients with achalasia and to establish their relationship with the presence of myenteric antiplexus antibodies in our geographic area. A total of 92 patients diagnosed with achalasia and two control groups with 275 healthy subjects were studied for HLA typing and 40 for autoantibodies determination. The myenteric antiplexus antibodies were positive in 50 patients (54.3%) and in 3 healthy subjects (7.5%) (P < 0.001). The patients showed a significantly higher frequency of DQA1*0103 and DQB1*0603 than was found in the controls. The heterodimer DQA1*0103–DQB1*0603 was increased in the patients [odds ratio (OR) = 2.57]. In regard to the association between the HLA DQA1 and DQB1 alleles and the antiplexus antibodies, these antibodies were found in greater prevalence in those patients with the DQA1*0103 and DQB1*0603 alleles, and the differences were statistically significant (OR = 3.17 and OR = 5.82, respectively). All of the women and 66.7% of the men with achalasia and the DQB1*0603 allele or the DQA1*0103–DQB1*0603 heterodimer were positive for antibodies.


Scandinavian Journal of Gastroenterology | 2003

Prevalence of mutations of the NOD2/CARD15 gene and relation to phenotype in Spanish patients with Crohn disease

Juan L. Mendoza; L. S. Murillo; Laura Fernandez; Amado Salvador Peña; R. Lana; E. Urcelay; Dulce M. Cruz-Santamaría; E. G. de la Concha; Manuel Díaz-Rubio; J. García‐Paredes

Background: We assessed the prevalence of R702W, G908R, and L1007fs coding mutations in the NOD2/CARD15 gene and the genotype–phenotype relation in Spanish patients with Crohn disease. Methods: A cohort of 204 unrelated patients with Crohn disease and 140 healthy controls were studied. The phenotype was established before commencement of genotyping. Genotyping of the R702W, G908R, and L1007fs gene polymorphisms of NOD2/CARD15 was performed by two independent laboratories using different techniques. In the case of discordant results, specific sequencing of DNA strands was performed. Results: At least one mutation was present in 32.8% of patients compared to 10.7% in controls (ORu2005=u20054.08, 95% CI 2.21 to 7.50). In patients with Crohn disease, the frequency of R702W, G908R, and L1007fs carriers was 13.7%, 8.3%, and 14.2%, respectively. Compound heterozygotes and homozygotes occurred in 3.4% and 2.9% of patients and in none of the controls. The correlation of genotype–Vienna classification showed a significant association with ileal disease (RRu2005=u20051.61, 95% CI 1.21–2.15, Pu2005=u20050.001) and an inverse association with colonic localization (RRu2005= 0.29, 95% CI 0.11–0.80, Pu2005=u20050.007). There was a significant association between G908R carriership and previous appendectomy, surgical interventions, and stricturing behavior. A gene‐dosage effect on phenotypic characteristics was not observed. Conclusions: In a Spanish population from Madrid, mutations of the NOD2/CARD15 gene were a marker of susceptibility to Crohn disease and were associated with ileal disease. Carriers of the G908R mutation showed a stricturing disease behavior, history of appendectomy, and surgical interventions over the course of the disease.


Archive | 2010

Adalimumab induction and maintenance therapy for ulcerative colitis patients previously treated with Infliximab.

Carlos Taxonera; Jesús Estellés; Ignacio Fernández-Blanco; Olga Merino; Ignacio Marín-Jiménez; Manuel Barreiro-de Acosta; Cristina Saro; Valle García-Sánchez; Elena Gento; Guillermo Bastida; Javier Perez-Gisbert; Isabel Vera; Pilar Martínez-Montiel; Sara Garcia-Moran; María Chaparro; Juan L. Mendoza

Aliment Pharmacol Ther 2011; 33: 340–348


Inflammatory Bowel Diseases | 2007

MDR1 polymorphisms and response to azathioprine therapy in patients with Crohn's disease.

Juan L. Mendoza; Elena Urcelay; R. Lana; M. Carmen Martín; Natalia López; Luis G. Guijarro; Julio Mayol; Carlos Taxonera; Emilio G. de la Concha; Amado Salvador Peña; Manuel Díaz-Rubio

Background To investigate the contribution of multidrug resistance 1 (MDR1) gene pharmacogenetics (G2677T/A and C3435T) to the efficacy of azathioprine in inducing remission in patients with Crohns disease (CD). Methods A cohort of 327 unrelated Spanish patients with CD recruited from a single center was studied. All patients were rigorously followed up for at least 2 years (mean time, 11.5 years). A case‐control analysis of MDR1 G2677T/A and C3435T SNPs and 2 loci haplotypes in 112 steroid‐dependent CD patients treated with azathioprine was performed. Patients were classified on the basis of response to azathioprine. Results A total 76 patients treated with azathioprine for longer than 3 months were included. Remission was achieved in 42 CD patients (55.3%). A higher frequency of the 2677TT genotype was found in nonresponders than in responders (17.65% versus 7.14%; OR = 2.8; 95% CI; 0.6–12.1; P = 0.11). Nonresponders to azathioprine were found to have a higher frequency of the 3435TT genotype than did CD patients who had achieved clinical remission (17.64% versus 4.76%; OR = 4.3; 95% CI, 0.8–22.8; P = 0.06). The 2677T/3435T haplotype was also more abundant in nonresponders (29.4% versus 20.2%), whereas the 2677G/3435C haplotype was more frequent in responders (58.3% versus 47.1%). Lack of response to azathioprine therapy in CD patients was 1.8‐fold greater in carriers of the 2677T/3435T haplotype than in carriers of the 2677G/3435C haplotype (OR = 1.8; 95% CI, 0.82–3.9; P = 0.14). Conclusions The results of our study indicate higher frequencies of the 2677TT and 3435TT genotypes and the 2677T/3435T haplotype in CD patients who did not respond to azathioprine. Additional replications in independent populations would confirm the real impact of these polymorphisms in response to azathioprine therapy. (Inflamm Bowel Dis 2007)


European Journal of Internal Medicine | 2011

Mucosal healing for predicting clinical outcome in patients with ulcerative colitis using thiopurines in monotherapy

Natalia López-Palacios; Juan L. Mendoza; Carlos Taxonera; R. Lana; José Miguel Esteban López-Jamar; Manuel Díaz-Rubio

BACKGROUNDnMucosal healing (MH) has emerged as a desirable treatment goal for patients with ulcerative colitis (UC). Currently little is known about the efficacy of using thiopurine immunosuppressants in monotherapy to achieve and maintain long-term MH in UC. This study analyzes the efficacy and the clinical impact of MH in patients with UC responded to thiopurine immunosuppressants in the long term.nnnMETHODSnAn open, observational, cohort study in 20 patients with UC had been in clinical remission in monotherapy with thiopurine immunosuppressants for at least 1 year. MH was assessed by endoscopy. The patients according to the Mayo Endoscopic Score (0 vs 1 and 2), were followed until the end of the study or patient relapse. (according to Truelove and Witts criteria).nnnRESULTSnMean treatment time was 5.4 years. Twelve (60%) patients presented a Mayo Endoscopic Score of 0. A total of 18 patients were followed up for a median of 27.1 months. After endoscopy, 4 patients (22.2%) presented relapse, with a mean time of 27.5 months for a score ≥1 (95% CI; 18.2-36.8) versus 54.3 months for a score=0 (95% CI 47.2-61.3) (p=0.032).nnnCONCLUSIONSnThis study shows the efficacy of thiopurine immunosuppressants in achieving mucosal healing in patients who respond to thiopurine immunosuppressants in the long term. We also observe the presence of endoscopy activity is not a rare event in this group of patients and is a predictor of early relapse.


Revista Espanola De Enfermedades Digestivas | 2008

Tratamiento de inducción y mantenimiento con adalimumab en la enfermedad de Crohn: un estudio abierto

N. López Palacios; Juan L. Mendoza; Carlos Taxonera; R. Lana; M. Fuentes Ferrer; Manuel Díaz-Rubio

BACKGROUND adalimumab has been shown in placebo-controlled clinical trials and uncontrolled studies to be effective in luminal and perianal fistulizing CD. OBJECTIVE to evaluate the efficacy and safety of adalimumab for induction and maintenance therapy in CD. METHODS twenty-two patients with CD treated with adalimumab (16 for luminal disease and 6 for active perianal fistulizing disease) were included. Twenty-one patients had previously received IFX. All patients received induction therapy with 160 mg s.c. at week 0, and 80 mg s.c. at week 2. Responders received maintenance therapy with 40 mg s.c. every 14 days. Response was assessed at 4 weeks after the initial dose, and classified as remission, partial response, or non-response. RESULTS after induction, 25% of patients with luminal disease had a complete remission, and 56.3% had a partial response. Clinical response was maintained in 71.6% of patients at 1 year, in 53.7% at 18 months, and in 35.8% at 48 months. No differences in response were observed between patients with hypersensitivity reactions or loss of response to IFX.All patients with perianal fistulizing disease (n = 6) had been previously treated with IFX. After induction 16.7% entered remission, and 66.7% had a partial response. All patients maintained remission or response over time, with a median follow-up of 15 months. CONCLUSIONS adalimumab is an effective and safe treatment for the induction and maintenance of response in luminal and perianal fistulizing CD. These results confirm that the findings obtained in controlled clinical trials are reproducible in clinical practice.


Revista Espanola De Enfermedades Digestivas | 2006

Polymorphisms in the interleukin-10 gene and relation to phenotype in patients with ulcerative colitis

Juan L. Mendoza; Elena Urcelay; R. Lana; A Martínez; Carlos Taxonera; E. G. de la Concha; Manuel Díaz-Rubio

BACKGROUND AND OBJECTIVESnInterleukin-10 (IL-10) has a key role in regulating mucosal inflammation in inflammatory bowel disease. In our population of Spanish ulcerative colitis (UC) patients, we have previously demonstrated that two polymorphisms (IL-10.G14 microsatellite allele and homozygous for the -1082G allele (guanine at position -1082)) in the IL-10 gene were susceptibility markers for disease. No data exist regarding the relationship of these IL-10 polymorphisms with phenotypic subpopulations in UC. Therefore, this study sought to examine the contribution of IL-10 polymorphisms to phenotypical variability in UC.nnnMATERIAL AND METHODSnA cohort of 215 Spanish unrelated patients with UC recruited in a single center was studied. All patients were rigorously phenotyped and followed for at least 3 years (mean time: 11.8 years). The clinical phenotype was established before genotyping. Genotyping was performed using polymerase chain reaction (PCR) assays.nnnRESULTSnPatients with UC included 129 (60%) men and 89 (40%) women. Mean age at diagnosis was 38 years, with a range of 8-83. Disease extent included 127 (59.1%) left-side patients and 88 (40.9%) extensive patients. Neither UC phenotype variable was associated with the presence of susceptibility polymorphisms (10G14 microsatellite and -1082G allele).nnnCONCLUSIONSnIn Madrids Spanish population of UC patients, the carrying of the ILG14 microsatellite or -1082G polymorphism in the IL-10 gene was not associated with phenotype of disease.


Scandinavian Journal of Gastroenterology | 2009

Analysis of a non-synonymous single nucleotide polymorphism of the human diamine oxidase gene (ref. SNP ID: rs1049793) in patients with Crohn's disease.

Natalia López Palacios; José A. G. Agúndez; Juan L. Mendoza; Elena García-Martín; Carmen Martínez; Manuel E. Fuentes Ferrer; José M. Ladero; Carlos Taxonera; Manuel Díaz-Rubio

Objective. To analyse the possible influence of a non-synonymous single nucleotide polymorphism (SNP) of the histamine-degrading enzyme diamine oxidase (DAO) on genetic susceptibility to Crohns disease (CD). Material and methods. In this prospective, case-control study, 210 unrelated Caucasian consecutive CD patients were recruited at the Inflammatory Bowel Disease Unit of a single tertiary centre (Hospital Clínico San Carlos) in Madrid, Spain. A total of 261 healthy volunteers from the same geographic area were also recruited and matched with patients. Both cases and controls were analysed for the presence of a non-synonymous SNP (rs1049793) of DAO using amplification-restriction procedures of the genotype obtained in a blood sample. Results. No significant differences were found in the distribution of carriers of the non-synonymous SNP of DAO between CD patients and controls (OR 1.2 (95% CI 0.9–1.6; p=0.3)). Nor were any differences found between carriers and non-carriers of the non-synonymous SNP in demographic characteristics, phenotypes, complications or treatment of CD. Conclusions. The study of a non-synonymous SNP (rs1049793) of DAO does not seem to be of use in assessing susceptibility to CD, either as a marker of disease activity or as a marker of clinical behaviour in patients with the disease.


World Journal of Gastroenterology | 2006

Polymorphisms in interleukin-10 gene according to mutations of NOD2/CARD15 gene and relation to phenotype in Spanish patients with Crohn’s disease

Juan L. Mendoza; Elena Urcelay; Raquel Lana; Alfonso Martínez; Carlos Taxonera; Emilio G. de la Concha; Manuel Díaz-Rubio


European Journal of Internal Medicine | 2003

P348 Effectiveness budesonide in patients with Crohn's disease

R. Lana; Juan L. Mendoza; A.I. Lérida; J. García-Paredes; Manuel Díaz-Rubio

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Manuel Díaz-Rubio

Complutense University of Madrid

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Carlos Taxonera

Complutense University of Madrid

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R. Lana

Complutense University of Madrid

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Elena Urcelay

Complutense University of Madrid

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Emilio G. de la Concha

Complutense University of Madrid

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A Martínez

Complutense University of Madrid

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Ana Gónzalez Vigo

Complutense University of Madrid

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Angeles Figueredo

Complutense University of Madrid

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Antonio Ruiz-de-León

Complutense University of Madrid

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