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Dive into the research topics where Hector Guadalajara is active.

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Featured researches published by Hector Guadalajara.


Diseases of The Colon & Rectum | 2012

Autologous expanded adipose-derived stem cells for the treatment of complex cryptoglandular perianal fistulas: a phase III randomized clinical trial (FATT 1: fistula Advanced Therapy Trial 1) and long-term evaluation.

Herreros; Mariano García-Arranz; Hector Guadalajara; Paloma De-La-Quintana; Dolores C. García-Olmo

Background: Autologous adipose-derived stem cells may represent a novel approach for the management of complex fistula-in-ano. After successful phase I and II clinical trials, a phase III trial was performed to investigate the safety and efficacy. Design: In this multicenter, randomized, single-blind, add-on clinical trial, 200 adult patients from 19 centers were randomly assigned to receive 20 million stem cells (group A, 64 patients), 20 million adipose-derived stem cells plus fibrin glue (group B, 60 patients), or fibrin glue (group C, 59 patients) after closure of the internal opening. Fistula healing was defined as reepithelization of the external opening and absence of collection >2 cm by MRI. If the fistula had not healed at 12 weeks, a second dose (40 million stem cells in groups A and B) was administered. Patients were evaluated at 24 to 26 weeks (primary end point) and at 1 year (long-term follow-up). Results: All results are according to the “blinded evaluator” assessment. After 24 to 26 weeks, the healing rate was 39.1%, 43.3%, 37.3% in groups A, B, and C (p = 0.79). At 1 year, the healing rates were 57.1%, 52.4%, and 37.3 % (p = 0.13). On analysis of the subpopulation treated at the technique’s pioneer center, healing rates were 54.55%, 83.33%, and 18.18%, at 24 to 26 weeks (p < 0.001). No SAEs were reported. Conclusions: In treatment of complex fistula-in-ano, a dose of 20 or 60 million adipose-derived stem cells alone or in combination with fibrin glue was considered a safe treatment, achieving healing rates of approximately 40% at 6 months and of more than 50% at 1-year follow-up. It was equivalent to fibrin glue alone. No statistically significant differences were found when the 3 groups where compared. Clinical trials registration: www.clinicaltrials.gov, identifier NCT00475410; Sponsor, Cellerix SA.


Case Reports in Medicine | 2010

Adipose-derived stem cells in Crohn's rectovaginal fistula.

Dolores C. García-Olmo; Dolores Herreros; Paloma De-La-Quintana; Hector Guadalajara; Jacobo Trébol; Tihomir Georgiev-Hristov; Mariano García-Arranz

Therapeutic options for recto-vaginal fistula in the setting of Crohns disease are limited and many data are available in the literature. The manuscript describes the history of a patient who has been the pioneer of our Clinical Trials in treating this disease in fistulizing Crohns disease environment. We believe it is the first time that a patient with this disease has been treated by adipose-derived stem cells in allogeneic form. The conclusion of our study with Mary is that the use of mesenchymal stem cells derived from adipose tissue is secure, either in autologous or allogeneic form. Furthermore, we have proved that if we use multi-dose and multiple applications on a patient, it does not produce any adverse effect, which confirms us the safety of using these cells in patients at least in the fistulizing Crohns disease environment.


World Journal of Gastroenterology | 2015

Recurrent anal fistulae: Limited surgery supported by stem cells

Damián García-Olmo; Hector Guadalajara; Ines Rubio-Perez; Maria Dolores Herreros; Paloma De-La-Quintana; Mariano García-Arranz

AIM To study the results of stem-cell therapy under a Compassionate-use Program for patients with recurrent anal fistulae. METHODS Under controlled circumstances, and approved by European and Spanish laws, a Compassionate-use Program allows the use of stem-cell therapy for patients with very complex anal fistulae. Candidates had previously undergone multiple surgical interventions that had failed to resolve the fistulae, and presented symptomatic recurrence. The intervention consisted of limited surgery (with closure of the internal opening), followed by local implant of stem cells in the fistula-tract wall. Autologous expanded adipose-derived stem cells were the main cell type selected for implant. The first evaluation was performed on the 8(th) postoperative week; outcome was classified as response or partial response. Evaluation one year after the intervention confirmed if complete healing of the fistula was achieved. RESULTS Ten patients (8 male) with highly recurrent and complex fistulae were treated (mean age: 49 years, range: 28-76 years). Seven cases were non-Crohns fistulae, and three were Crohns-associated fistulae. Previous surgical attempts ranged from 3 to 12. Two patients presented with preoperative incontinence (Wexner scores of 12 and 13 points). After the intervention, six patients showed clinical response on the 8(th) postoperative week, with a complete cessation of suppuration from the fistula. Three patients presented a partial response, with an evident decrease in suppuration. A year later, six patients (60%) remained healed, with complete reepithelization of the external opening. Postoperative Wexner Scores were 0 in six cases. The two patients with previous incontinence improved their scores from 12 to 8 points and from 13 to 5 points. No adverse reactions or complications related to stem-cell therapy were reported during the study period. CONCLUSION Stem cells are safe and useful for treating anal fistulae. Healing can be achieved in severe cases, sparing fecal incontinence risk, and improving previous scoring.


Stem Cells Translational Medicine | 2016

Treatment of Crohn's-Related Rectovaginal Fistula With Allogeneic Expanded-Adipose Derived Stem Cells: A Phase I–IIa Clinical Trial

Mariano García-Arranz; Maria Dolores Herreros; Carolina de Carlos González-Gómez; Paloma de la Quintana; Hector Guadalajara; Tihomir Georgiev-Hristov; Jacobo Trébol; Damián García-Olmo

The aim of this clinical trial was to determine the safety and feasibility of expanded allogeneic adipose‐derived stem cells to treat Crohn’s‐related rectovaginal fistula (CRRVF). We designed a phase I–II clinical trial (https://ClinicalTrials.gov, NCT00999115) to treat 10 patients with CRRVF. Patients receiving biological therapy during follow‐up were excluded. Curettage was performed, and a vaginal or rectal flap was added if the surgeon considered it necessary. The therapeutic protocol included intralesional injection of 20 million stem cells in the vaginal walls (submucosal area) and fistula tract. Healing was evaluated 12 weeks later. If the fistula had not healed, a second dose of 40 million stem cells was administered. Patient follow‐up was 52 weeks from last cell injection. Healing was defined as re‐epithelialization of both vaginal and rectal sides and absence of vaginal drainage. Cytokines and immunological blood tests were monitored. Serious adverse events or rejection issues were not observed. Five patients were excluded because biologic drugs were required to treat a Crohns disease flare‐up during follow‐up. Cytokine profiles and immunotoxicity assays showed no statistically significant alterations. Sixty percent of the nonexcluded patients achieved a complete healing. Expanded allogeneic adipose‐derived stem‐cell injection is a safe and feasible therapy for treating CRRVF, and the healing success rate seems promising (60%). The results of this trial encourage further exploration into this therapy.


Cancer Detection and Prevention | 2008

The concentration of deoxyribonucleic acid in plasma from 73 patients with colorectal cancer and apparent clinical correlations

Hector Guadalajara; Carolina Domínguez-Berzosa; Mariano García-Arranz; Maria Dolores Herreros; Isabel Pascual; Raquel Sanz-Baro; Dolores C. García-Olmo; Damián García-Olmo

BACKGROUND Detection of cell-free plasma DNA has considerable potential as a tool for the diagnosis and assessment of the prognosis of many types of cancer. The aim of the present study was to quantify, by spectrophotometry, the cell-free DNA in plasma samples from patients with colorectal cancer at different stages of the disease and to attempt to correlate the resultant values with the clinical picture. METHODS We reviewed the medical reports of 73 patients, who had undergone resection of primary colorectal cancer. Samples of blood had been taken from each patient immediately prior to surgery. DNA was extracted from samples of plasma and quantified, by spectrophotometry, after a storage period of no longer than 2 years in 89% of the cases examined. RESULTS The mean(+/-S.D.) concentration of DNA in plasma samples was 108+/-156 ng/microl. We found a statistically significant correlation between the concentration of DNA and the presence of metastases (mainly liver metastases). CONCLUSION The detection and quantitation of cell-free DNA in plasma, using this simple technique, might be of clinical value for the surveillance of colon cancer patients and the detection of metastases.


Nature Medicine | 2016

Chromatin immunoprecipitation from fixed clinical tissues reveals tumor-specific enhancer profiles

Paloma Cejas; Lewyn Li; Nicholas K. O'Neill; Melissa Duarte; Prakash Rao; Michaela Bowden; Chensheng W. Zhou; Marta Mendiola; Emilio Burgos; Jaime Feliu; Hector Guadalajara; Victor Moreno; Damián García-Olmo; Joaquim Bellmunt; Stephanie A. Mullane; Michelle S. Hirsch; Christopher Sweeney; Andrea L. Richardson; X. Shirley Liu; Myles Brown; Ramesh A. Shivdasani; Henry W. Long

Extensive cross-linking introduced during routine tissue fixation of clinical pathology specimens severely hampers chromatin immunoprecipitation followed by next-generation sequencing (ChIP-seq) analysis from archived tissue samples. This limits the ability to study the epigenomes of valuable, clinically annotated tissue resources. Here we describe fixed-tissue chromatin immunoprecipitation sequencing (FiT-seq), a method that enables reliable extraction of soluble chromatin from formalin-fixed paraffin-embedded (FFPE) tissue samples for accurate detection of histone marks. We demonstrate that FiT-seq data from FFPE specimens are concordant with ChIP-seq data from fresh-frozen samples of the same tumors. By using multiple histone marks, we generate chromatin-state maps and identify cis-regulatory elements in clinical samples from various tumor types that can readily allow us to distinguish between cancers by the tissue of origin. Tumor-specific enhancers and superenhancers that are elucidated by FiT-seq analysis correlate with known oncogenic drivers in different tissues and can assist in the understanding of how chromatin states affect gene regulation.


Diseases of The Colon & Rectum | 2014

Prevalence of abnormal anal cytology and high-grade squamous intraepithelial lesions among a cohort of HIV-infected men who have sex with men.

Elena Sendagorta; Pedro Herranz; Hector Guadalajara; Jose I. Bernardino; Jose María Viguer; María José Beato; Damián García-Olmo; Peña Jm

BACKGROUND: The incidence of anal cancer among HIV-infected patients is higher than that in other populations. Anal high-grade squamous intraepithelial lesions are considered precursors to invasive squamous-cell carcinomas and are strongly associated to high-risk human papillomavirus infection. OBJECTIVE: The aim of this study is to determine the prevalence of anal high-grade squamous intraepithelial lesions through screening based on cytology and high-resolution anoscopy with biopsy in a cohort of HIV-infected men who have sex with men. DESIGN: This investigation is an observational cross-sectional cohort study. SETTING: The study was conducted in the HIV unit of a tertiary hospital in Spain. PATIENTS: Three hundred HIV-infected men who have sex with men participated. Physical examination led to a diagnosis of perianal squamous-cell carcinoma and high-grade squamous intraepithelial lesions in 2 patients who were then excluded. INTERVENTIONS: Anal liquid cytology was performed. Patients with cytological abnormalities underwent high-resolution anoscopy and biopsy. MAIN OUTCOME MEASURE: The primary outcome measured was biopsy-proven high-grade squamous intraepithelial lesions. RESULTS: The median age was 41 ± 10.5 years. The mean and nadir CD4 cell counts were 651 ± 205 cells/mm3 (interquartile range, 438–800) and 273 ± 205 cells/mm3 (interquartile range, 131–362). High-risk human papillomavirus was detected in 80.9% of patients, and human papillomavirus 16 was detected in 35.9% of patients. The mean number of human papillomavirus genotypes was 4.6 ± 2.9 (CI, 2–6). Anal cytology was abnormal in 40.9% of patients (n = 122/298; interquartile range, 35.4%–46.6%). High-resolution anoscopy and biopsies were performed in 119 patients. The results of histological analyses were as follows: normal, 7.7% (n = 23); condyloma, 4.3% (n = 13); anal intraepithelial neoplasia 1, 5.7% (n = 17); anal intraepithelial neoplasia 2, 14% (n = 42); and anal intraepithelial neoplasia 3, 8% (n = 24). The overall prevalence of high-grade squamous intraepithelial lesions among patients with abnormal cytology was 54% (95% CI, 45.1%–62.8%). A diagnosis of high-grade squamous intraepithelial lesions was associated with human papillomavirus 16 and human papillomavirus 51 infection, and with detection of a higher number of human papillomavirus genotypes. LIMITATIONS: High-resolution anoscopy was only performed in patients with abnormal cytology. CONCLUSIONS: The prevalence of high-risk human papillomavirus infection and high-grade squamous intraepithelial lesions is high in our cohort. Physical examination enabled straightforward diagnosis of perianal high-grade squamous intraepithelial lesions and squamous-cell carcinoma in 2 patients.


International Journal of Molecular Sciences | 2016

KRAS G12V Mutation Detection by Droplet Digital PCR in Circulating Cell-Free DNA of Colorectal Cancer Patients

Susana Olmedillas López; Dolores C. García-Olmo; Mariano García-Arranz; Hector Guadalajara; Carlos Pastor; Damián García-Olmo

KRAS mutations are responsible for resistance to anti-epidermal growth factor receptor (EGFR) therapy in colorectal cancer patients. These mutations sometimes appear once treatment has started. Detection of KRAS mutations in circulating cell-free DNA in plasma (“liquid biopsy”) by droplet digital PCR (ddPCR) has emerged as a very sensitive and promising alternative to serial biopsies for disease monitoring. In this study, KRAS G12V mutation was analyzed by ddPCR in plasma DNA from 10 colorectal cancer patients and compared to six healthy donors. The percentage of KRAS G12V mutation relative to wild-type sequences in tumor-derived DNA was also determined. KRAS G12V mutation circulating in plasma was detected in 9 of 10 colorectal cancer patients whose tumors were also mutated. Colorectal cancer patients had 35.62 copies of mutated KRAS/mL plasma, whereas in healthy controls only residual copies were found (0.62 copies/mL, p = 0.0066). Interestingly, patients with metastatic disease showed a significantly higher number of mutant copies than M0 patients (126.25 versus 9.37 copies/mL, p = 0.0286). Wild-type KRAS was also significantly elevated in colorectal cancer patients compared to healthy controls (7718.8 versus 481.25 copies/mL, p = 0.0002). In conclusion, KRAS G12V mutation is detectable in plasma of colorectal cancer patients by ddPCR and could be used as a non-invasive biomarker.


Stem Cells Translational Medicine | 2015

First-in-Human Case Study: Pregnancy in Women With Crohn’s Perianal Fistula Treated With Adipose-Derived Stem Cells: A Safety Study

Raquel Sanz-Baro; Mariano García-Arranz; Hector Guadalajara; Paloma de la Quintana; Maria Dolores Herreros; Damián García-Olmo

The aim of this study was to determine whether treatment with adipose‐derived stem cells (ASCs) had any influence on fertility, course of pregnancy, newborn weight, or physical condition of newborns. We performed a retrospective study of patients with a desire to become pregnant after having received intralesional injection of autologous ASCs for the treatment of perianal or rectovaginal fistula associated with Crohns disease. We collected data on the resulting pregnancies, deliveries, and newborns of these patients. ASCs were expanded in vitro and characterized according to the international guidelines for cell surface markers (clusters of differentiation) and differentiated to adipocytes, chondrocytes, and osteocytes prior to implantation (except first implant in 2002). We analyzed five young women with Crohns disease treated with ASCs: one for rectovaginal and perianal fistula, two for rectovaginal fistula only, and two for perianal fistula only. All patients received 2 doses of 20 million and 40 million cells at an interval of 3–4 months. Another patient received 2 doses of 6.6 million and 20 million ASCs with 9 months between each dose. Fertility and pregnancy outcomes were not affected by cell therapy treatment. No signs of treatment‐related malformations were observed in the neonates by their respective pediatricians. In the patients studied, cell therapy with ASCs did not affect the course of pregnancy or newborn development.


Histopathology | 2010

Histopathological analysis of human specimens removed from the injection area of expanded adipose-derived stem cells

Mariano García-Arranz; Ulises Gómez-Pinedo; David Hardisson; Dolores Herreros; Hector Guadalajara; Ignacio García-Gómez; Jose Manuel Garcia-Verdugo; Damián García-Olmo

BNCT. SHH and PTCH1 were both detected in human fetal notochord at 12 and 28 weeks gestational age, but not at 24 or 34 weeks. All five intervertebral discs were negative for PTCH1. SHH and PTCH1 were coexpressed in 62% (eight of 13) of chondrosarcomas. SHH and its cognate receptor PTCH1 are coexpressed in human notochord, at least up to 28 weeks gestational age. Whereas SHH and PTCH1 are observed less frequently in notochord obtained later in development and in the mature nucleus pulposus, this receptor– ligand pair is coexpressed in most chordomas, raising the possibility that autocrine or paracrine SHH signalling may be important for the neoplastic transformation of notochordal rests or BNCTs. The status of the SHH signalling pathway in BNCT is unclear, and further study of additional cases is required. In addition, given the important role of the Indian hedgehog signalling in chondrogenesis, this pathway may also be activated aberrantly in malignant cartilage tumours. Whether aberrant activation of this signalling pathway contributes to chordomagenesis should be investigated further in putative precursor lesions and murine models of chordoma in development. Justin M M Cates Doha M Itani Cheryl M Coffin Brian D Harfe Department of Pathology, Vanderbilt University Medical Center, Nashville, TN, and Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA

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Dive into the Hector Guadalajara's collaboration.

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Damián García-Olmo

Autonomous University of Madrid

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Mariano García-Arranz

Autonomous University of Madrid

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Dolores C. García-Olmo

Autonomous University of Madrid

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Paloma De-La-Quintana

Autonomous University of Madrid

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Dolores Herreros

Autonomous University of Madrid

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Jacobo Trébol

Hospital Universitario La Paz

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Carlos Pastor

Autonomous University of Madrid

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Elena Sendagorta

Hospital Universitario La Paz

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Paloma de la Quintana

Hospital Universitario La Paz

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