Search results for "Purine"
showing 10 items of 229 documents
CD73-generated extracellular adenosine in chronic lymphocytic leukemia creates local conditions counteracting drug-induced cell death
2011
Abstract Extracellular adenosine (ADO), generated from ATP or ADP through the concerted action of the ectoenzymes CD39 and CD73, elicits autocrine and paracrine effects mediated by type 1 purinergic receptors. We have tested whether the expression of CD39 and CD73 by chronic lymphocytic leukemia (CLL) cells activates an adenosinergic axis affecting growth and survival. By immunohistochemistry, CD39 is widely expressed in CLL lymph nodes, whereas CD73 is restricted to proliferation centers. CD73 expression is highest on Ki-67+ CLL cells, adjacent to T lymphocytes, and is further localized to perivascular areas. CD39+/CD73+ CLL cells generate ADO from ADP in a time- and concentration-dependen…
Complex regional pain syndrome:intradermal injection of phenylephrine evokes pain and hyperalgesia in a subgroup of patients with upregulated α1-adre…
2018
The aim of this study was to determine whether upregulated cutaneous expression of α1-adrenoceptors (α1-AR) is a source of pain in patients with complex regional pain syndrome (CRPS). Immunohistochemistry was used to identify α1-AR on nerve fibres and other targets in the affected and contralateral skin of 90 patients, and in skin samples from 38 pain-free controls. The distribution of α1-AR was compared between patients and controls, and among subgroups of patients defined by CRPS duration, limb temperature asymmetry, and diagnostic subtype (CRPS I vs CRPS II). In addition, α1-AR expression was investigated in relation to pain and pinprick hyperalgesia evoked by intradermal injection of th…
Relaxation and cyclic GMP levels in response to sildenafil in human pulmonary arteries from donors.
2005
We measured cyclic GMP formation and relaxation response to sildenafil given either alone or in combination with sodium nitroprusside (SNP) in pulmonary arteries obtained from 13 multi-organ donors. Sildenafil (10(-9)-10(-4) M) caused concentration-dependent relaxations and amplified the relaxation induced by SNP. Relaxation was unaffected by endothelium removal or by pre-treatment with the inhibitor of nitric oxide synthase L-NMMA (10(-4) M). SNP (10(-7) M) caused elevation of cyclic GMP levels that was potentiated by sildenafil (10(-6) M). Thus, the enhancement of SNP-induced relaxation by sildenafil is mainly due to an increase in cyclic GMP accumulation.
Risk of Colorectal High-Grade Dysplasia and Cancer in a Prospective Observational Cohort of Patients with Inflammatory Bowel Disease.
2013
International audience; BACKGROUND AND AIMS:: There is an unclear risk of colonic high-grade dysplasia (HGD) and colorectal cancer (CRC) among patients with inflammatory bowel disease (IBD) treated with immunosuppressants. We analyzed data on CRC development among patients with IBD enrolled in the observational cohort Cancers et Surrisque Associé aux Maladies Inflammatoires Intestinales En France (CESAME). METHODS:: We followed and collected data from 19,486 patients with IBD (60.3% with Crohn's disease, 30.1% receiving thiopurine therapy) enrolled in CESAME from May 2004 and June 2005, and followed until December 2007. When the study began, 2841 patients (14.6%) were characterized as havin…
Effects of sildenafil on human penile blood vessels.
2000
Abstract Objectives. To investigate the effects of sildenafil on human penile blood vessels and evaluate the interaction of sildenafil with neurogenic-mediated responses. Sildenafil is currently used in the treatment of erectile dysfunction. Methods. Penile dorsal arteries and deep dorsal veins were obtained from 14 multiorgan donors. Vascular rings were suspended in organ bath chambers, and the isometric tension was recorded. We then studied the effects of sildenafil on precontracted vessels and the neurogenic (noradrenergic and nitrergic) responses. Results. Sildenafil (10 −9 to 3 × 10 −6 M) caused concentration-dependent relaxation and amplified the relaxation induced by sodium nitroprus…
Switching to a Second Thiopurine in Adult and Elderly Patients With Inflammatory Bowel Disease: A Nationwide Study From the ENEIDA Registry
2020
Abstract Background and Aims Although commonly used in inflammatory bowel disease [IBD], thiopurines frequently cause intolerance, and switching to a second thiopurine has only been reported in some small series. Ours aims in this study were to evaluate the safety of switching to a second thiopurine in a large cohort, and to assess the impact of age on tolerance. Methods Adult IBD patients from the ENEIDA registry, who were switched to a second thiopurine due to adverse events [excluding malignancies and infections], were identified. At the beginning of thiopurine treatment, patients were divided by age into two groups: 18–50 and over 60 years of age. The rate and concordance of adverse eve…
Increased Risk of Acute Myeloid Leukemias and Myelodysplastic Syndromes in Patients Who Received Thiopurine Treatment for Inflammatory Bowel Disease.
2014
Background & Aims Treatment with immunosuppressive thiopurines such as azathioprine is associated with an increased risk of leukemogenesis. We assessed the risk of myeloid disorders, such as acute myeloid leukemia and myelodysplastic syndromes, in a large cohort of patients with inflammatory bowel disease (IBD) in France. Methods We performed a prospective observational study of 19,486 patients with IBD enrolled in the Cancers Et Surrisque Associe aux Maladies inflammatoires intestinales En France (CESAME) study from May 2004 through June 2005; patients were followed through December 31, 2007. The incidence of myeloid disorders in the general population, which was used for reference, was de…
Tolerability profile of thiopurines in inflammatory bowel disease: a prospective experience
2017
The occurrence of thiopurine-related adverse events (AEs) may complicate the management of patients with inflammatory bowel disease (IBD). We aimed to evaluate the tolerability of thiopurines in a current IBD setting.All consecutive patients who started a treatment with azathioprine (AZA) from January 2010 to March 2016 were entered in a prospectively maintained database, and the AEs which led to the permanent discontinuation of the drug were reported.Two hundred and fifty three patients were included. Median total follow-up was 32 months (range: 0.2-75 months). At the end of the study, AZA was discontinued in 160 patients (63.2%). The main reason leading to drug withdrawal was the occurren…
Thiopurine adherence: high prevalence with low impact in UC outcomes
2021
Introduction Thiopurines are used as maintenance therapy in patients with ulcerative colitis (UC). There are contradictory results regarding the relationship between adherence to treatment and risk of relapse. Objectives To quantify and evaluate the trends in thiopurines prescription rates, and to determine the impact and risk factors of non-adherence. Methods Analytical, observational and retrospective study of UC patients, on thiopurines, included in the ENEIDA single-center registry from October 2017 to October 2019. We included adult patients under clinical remission at the beginning of the study on thiopurines maintenance treatment for at least 6 months before recruitment. Adherence wa…
Excess primary intestinal lymphoproliferative disorders in patients with inflammatory bowel disease.
2012
International audience; BACKGROUND: It remains to be shown whether inflammatory bowel disease (IBD) is associated with an increased risk of primary intestinal lymphoproliferative disorders (PILD). We assessed this risk in the CESAME French nationwide prospective observational cohort. METHODS: In all, 680 gastroenterologists enrolled 19,486 patients with IBD (Crohn's disease in 60.3%) from May 2004 to June 2005. Follow-up ended on 31 December 2007. Available biopsy samples and surgical specimens from patients with PILD (n = 14) were centralized for review. The reference incidence of PILD in the general population was obtained from the Côte d'Or registry and was used as a comparator to assess…