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AB0826 Keep an Eye on the Back: Spondyloarthritis in Patients with Acute Anterior Uveitis. Ann Rheum Dis 2022. [DOI: 10.1136/annrheumdis-2022-eular.3252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BackgroundPatients with acute anterior uveitis (AAU) have an increased risk for concomitant spondyloarthritis (SpA). Different referral strategies have been proposed to identify AAU patients with high probability of SpA, among them an Assessment of SpondyloArthritis international Society(ASAS)-based referral strategy focusing on patients with chronic back pain starting before the age of 45 years and the Dublin Uveitis Evaluation Tool (DUET) also including psoriasis, HLA-B27 and arthralgia (Poddubnyy et al., Haroon et al., both ARD 2015).ObjectivesTo analyse the prevalence of SpA in patients with AAU, to identify parameters associated with SpA presence, and to evaluate referral algorithms.MethodsPatients with non-infectious AAU underwent structured rheumatologic assessment including magnetic resonance imaging of sacroiliac joints allowing a definitive diagnosis/exclusion of concomitant SpA. Fisher’s exact test and Mann–Whitney U test were used to compare AAU patients with and without SpA. Furthermore, logistic regression analyses were performed. Sensitivity, specificity, positive predictive value, positive and negative likelihood ratios were analysed for referral strategies.ResultsThe 189 AAU patients with complete rheumatologic assessment and SIJ imaging were 40.8 years old, and 55% were males. SpA was diagnosed in 106 AAU patients (56%). The majority (93%) had predominantly axial SpA, 7 patients peripheral SpA. In 74 patients (70%), the SpA diagnosis was established for the first time. Pelvic X-rays were available for 88 (89%) of the axSpA patients, 66% of whom were classified as having radiographic axSpA.SpA was equally frequent in patients experiencing the first episode of AAU and in patients with recurrent disease. In our cohort, AAU patients with and without underlying SpA showed no differences in their ophthalmologic examination. In multivariable logistic regression analysis, psoriasis (OR 12.5 [95%CI 1.3-120.2]), HLA-B27 positivity (OR 6.3 [95%CI 2.4-16.4]), elevated CRP (OR 4.8 [95%CI 1.9-12.4]) and male sex (OR 2.1 [95%CI 1.1-4.2]) were associated with SpA presence.Table 1.Parameters associated with the presence of spondyloarthritis in patients with acute anterior uveitis.univariablemultivariableOR95%CIOR95%CIPsoriasis (ever)14.6(1.9; 112.4)12.5(1.3; 120.2)HLA-B27 positivity6.2(2.7; 14.6)6.3(2.4; 16.4)Elevated CRP (≥ 5 mg/l)4.1(1.8; 9.0)4.8(1.9; 12.4)Male sex2.2(1.2; 4.0)2.1(1.1; 4.2)Inflammatory back pain (ASAS definition)2.1(1.2; 3.9)1.9(0.9; 4.0)Any peripheral manifestation (ever)1.9(1.1; 3.5)1.9(0.9; 3.8)Age in years1.0(1.0; 1.0)1.0(1.0; 1.0)Univariable and multivariable logistic regression analyses. ASAS Assessment of SpondyloArthritis international Society; CRP C-reactive protein; OR odds ratio; CI confidence interval.The Dublin Uveitis Evaluation Tool showed higher specificity for SpA recognition than the ASAS referral tool (42% vs. 28%), which had slightly higher sensitivity (78% vs. 80%). However, both referral strategies would have missed more than 20% of SpA patients.ConclusionWe revealed a high prevalence of overall and previously undiagnosed SpA in AAU patients. Therefore, we propose rheumatologic evaluation for all AAU patients with musculoskeletal symptoms. Rheumatologists should consider that SpA in AAU patients might present “atypically” with back pain starting after 45 years and lasting shorter than 3 months.Figure 1.Performance of Referral Strategies in Patients with Acute Anterior Uveitis. Dublin Uveitis Evaluation Tool (DUET) and an ASAS-based referral tool (ASAS). + respective tool fulfilled, - not fulfilled. ASAS Assessment of SpondyloArthritis international Society; AxSpA axial spondyloarthritis, pSpA peripheral spondyloarthritis.AcknowledgementsThe authors would like to thank the rheumatologists S. Lüders, B. Muche and A.-K. Weber for participating in the clinical data acquisition; and A. Langdon and L. Meinke for their support monitoring and coordinating this study. Furthermore, we are grateful to all participating ophthalmologists who included their patients in this study and to all patients. The study was supported by an unrestricted research grant from AbbVie. AbbVie had no role in the study design or in the collection, analysis, or interpretation of the data, the writing of the manuscript, or the decision to submit the manuscript for publication. Dr. Judith Rademacher and Dr. Dominika Pohlmann are participants in the BIH-Charité Clinician Scientist Program funded by the Charité –Universitätsmedizin Berlin and the Berlin Institute of Health.Disclosure of InterestsJudith Rademacher: None declared, Hanna Müllner: None declared, Torsten Diekhoff Speakers bureau: AbbVie, MSD, Novartis, Canon MS, Consultant of: Lilly, Hildrun Haibel Speakers bureau: AbbVie, MSD, Janssen, Roche, Pfizer, Sobi, Consultant of: Janssen, Sobi, Novartis, Sabrina Igel: None declared, Dominika Pohlmann Speakers bureau: Bayer, Consultant of: AbbVie, Celgene, Janssen, Novartis, UCB, Grant/research support from: Bayer, Allergan, Fabian Proft Speakers bureau: AMGEN, AbbVie, BMS, Celgene, Janssen, MSD, Novartis, Pfizer, Roche, UCB, Consultant of: AbbVie, Celgene, Janssen, Novartis, UCB, Grant/research support from: UCB, Novartis, Lilly, Mikhail Protopopov Consultant of: Novartis, Valeria Rios Rodriguez Consultant of: AbbVie, Falk e.V., Murat Torgutalp: None declared, Uwe Pleyer Shareholder of: stock or stock options from Novartis, BionTec, Speakers bureau: AbbVie, Alimera, Novartis, Grant/research support from: AbbVie, Denis Poddubnyy Speakers bureau: AbbVie, Bristol-Myers Squibb, Eli Lilly, MSD, Novartis, Pfizer and UCB, Consultant of: AbbVie, Biorad, Eli Lilly, Gilead, GlaxoSmithKline, Janssen, MSD, Novartis, Pfizer, Samsung Bioepis and UCB, Grant/research support from: AbbVie, Eli Lilly, MSD, Novartis, Pfizer
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OP0050 INTRAARTICULAR MORPHINE IN CHRONIC KNEE-ARTHRITIS – RESULTS OF A RANDOMIZED PLACEBO-CONTROLLED TRIAL. Ann Rheum Dis 2022. [DOI: 10.1136/annrheumdis-2022-eular.1602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BackgroundPatients with chronic inflammatory arthritis (e.g. rheumatoid arthritis; RA) or inflammatory exacerbations of chronic degenerative joint diseases (e.g. osteoarthritis; OA) suffer from recurrent pain, restricted function and reduction of daily activities. The current standard of intraarticular (i.a.) therapy is the injection of steroids, which can increase risk of infection, cartilage degenerations, and other well-known systemic side effects. A novel approach without such complications could be the activation of peripheral opioid receptors, e.g. by i.a. application of small, systemically inactive doses of morphine.ObjectivesThe aim of this randomized placebo-and active drug controlled double blind trial was to investigate reduction of pain in chronic knee arthritis patients following i.a. injections of morphine, a standard steroid (triamcinolone), or placebo. The primary hypothesis was that i.a. morphine results in significantly lower pain scores than placebo. The primary outcome parameter was reduction of the Visual Analogue Scale (VAS) pain at day 7.MethodsAdult patients with chronic knee arthritis because of osteoarthritis (OA) or inflammatory arthritis (IA, rheumatoid arthritis, psoriatic arthritis, spondyloarthritis, oligoarthritis or monarthritis) and a high level of pain (VAS pain ≥ 4 out of 10) at baseline received a single dose of either morphine 3 mg i.a., or triamcinolone 40 mg i.a., or placebo (NaCl 0.9%) i.a., Patients were monitored closely throughout the entire study period with a total of 4 visits over weeks and documented pain in the morning and evening in a patient´s diary. Safety data was collected during the whole study period. P-values were calculated using two-sided T-tests.Results114 patients were screened, 93 were treated and 89 (96%) completed day 7. Of these n= 61 (66%) were diagnosed with OA and n= 32 (34%) with IA 48 (52%) patients were female, mean age was 58.5 (SD 14 years) and mean disease duration 6.7 years (median 2 years, range <1 year – 42 yearss, IQR <1 – 10 years). The mean VAS pain improvement at day 7 for morphine, triamcinolone and placebo was -22.8, -37.7, and -19.8 respectively. The differences were not significant (p=0.69) for placebo vs. morphine, but significant for placebo vs. triamcinolone and for triamcinolone vs. morphine (p=0.013 and p=0.006). Mean improvements of the everyday pain documentation are shown in Figure 1. During the study period, there were no serious adverse events and 45 adverse events, most of them were mild.Figure 1.Mean VAS pain over one week in patients with chronic knee arthritis treated with morphine, triamcinolone or placebo as a single intraarticular injection.ConclusionIn this randomized, placebo and active controlled double blind trial a single dose of 3 mg i.a. administered morphine did not lead to significant improvements in comparison to placebo and was inferior to triamcinolone at day 7. The same was true during the first 7 days as shown in the pain documentation in patient diaries. These data does not support the use of i.a. morphine for pain reduction in patients with chronic arthritis.Disclosure of InterestsHildrun Haibel Speakers bureau: AbbVie, MSD, Janssen, Roche and Pfizer, Consultant of: Roche, Boehringer, Janssen, MSD, Novartis, and Sobi, Grant/research support from: BMBF Neuroimpa 01EC1403F, Joachim Sieper Speakers bureau: Abbvie, Janssen, Lilly, Merck,Novartis, UCB, Consultant of: Abbvie, Lilly, Merck, Novartis, UCB, Denis Poddubnyy Speakers bureau: AbbVie, Bristol Myers Squibb, Eli Lilly, MSD, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Biocad, Eli Lilly, Gilead, GlaxoSmithKline, MSD, Novartis, Pfizer, Samsung Bioepis, and UCB, Grant/research support from: AbbVie, Eli Lilly, MSD, Novartis, and Pfizer, Valeria Rios Rodriguez: None declared, Fabian Proft Speakers bureau: Abbvie, BMS, MSD, Novartis, Pfizer, Roche and UCB, Consultant of: Abbvie, BMS, MSD, Novartis, Pfizer, Roche and UCB, Grant/research support from: Novartis, Judith Rademacher: None declared, Sabrina Igel: None declared, Peter Martus: None declared, Christoph Stein Grant/research support from: BMBF Neuroimpa 01EC1403F.
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Hepatic sinusoidal obstruction syndrome and short-term application of 6-thioguanine in pediatric acute lymphoblastic leukemia. Leukemia 2021; 35:2650-2657. [PMID: 33714975 PMCID: PMC8410596 DOI: 10.1038/s41375-021-01203-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 01/27/2021] [Accepted: 02/18/2021] [Indexed: 11/21/2022]
Abstract
Long-term treatment with 6-thioguanine (6-TG) for pediatric acute lymphoblastic leukemia (ALL) is associated with high rates of hepatic sinusoidal obstruction syndrome (SOS). Nevertheless, current treatment continues to use short-term applications of 6-TG with only sparse information on toxicity. 6-TG is metabolized by thiopurine methyltransferase (TPMT) which underlies clinically relevant genetic polymorphism. We analyzed the association between hepatic SOS reported as a serious adverse event (SAE) and short-term 6-TG application in 3983 pediatric ALL patients treated on trial AIEOP-BFM ALL 2000 (derivation cohort) and defined the role of TPMT genotype in this relationship. We identified 17 patients (0.43%) with hepatic SOS, 13 of which with short-term exposure to 6-TG (P < 0.0001). Eight of the 13 patients were heterozygous for low-activity TPMT variants, resulting in a 22.4-fold (95% confidence interval 7.1-70.7; P ≤ 0.0001) increased risk of hepatic SOS for heterozygotes in comparison to TPMT wild-type patients. Results were supported by independent replication analysis. All patients with hepatic SOS after short-term 6-TG recovered and did not demonstrate residual symptoms. Thus, hepatic SOS is associated with short-term exposure to 6-TG during treatment of pediatric ALL and SOS risk is increased for patients with low-activity TPMT genotypes.
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Stereoselective quantification of phase 1 and 2 metabolites of clomiphene in human plasma and urine. Talanta 2021; 221:121658. [DOI: 10.1016/j.talanta.2020.121658] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/09/2020] [Accepted: 09/10/2020] [Indexed: 01/21/2023]
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The phenotype of adverse drug effects: Do emergency visits due to adverse drug reactions look different in older people? Results from the ADRED study. Br J Clin Pharmacol 2020; 86:2144-2154. [PMID: 32250457 PMCID: PMC7576634 DOI: 10.1111/bcp.14304] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 02/03/2020] [Accepted: 03/10/2020] [Indexed: 12/15/2022] Open
Abstract
AIMS Older patients in particular suffer from adverse drug reactions (ADR) when presenting in the emergency department. We aimed to characterise the phenotype of those ADRs, to be able to recognise an ADR in older patients. METHODS Cases of ADRs in emergency departments collected within the multicentre prospective observational study (ADRED) were analysed (n = 2215). We analysed ADR-associated diagnoses, symptoms and their risk profiles. We present frequencies and odds ratios (OR) with 95% confidence intervals for adults (18-64 years) compared to older adults (≥65 years; young-old 65-79, old-old ≥80 years) and regression coefficients (B) for each year of age. RESULTS Most prominent differences were seen for drug-associated confusion, dehydration, and bradycardia (OR 6.70 [1.59-28.27], B .054; OR 6.02 [2.41-15.03], B .081, and 4.82 [2.21-10.54], B .040), more likely seen in older adults. Bleedings were reported in all age groups, but gastrointestinal bleedings occurred with more than doubled chance in older adults (OR 2.46 [1.77-3.41], B .030), likewise did other bleedings such as haemorrhage from respiratory passages (OR 2.89 [1.37-6.11], B.036). Falls were more likely in older adults (OR 2.84 [1.77-4.53], B .030), while dizziness was frequent in both age groups. CONCLUSION Our data point to differences in symptoms of ADRs between adults and older individuals, with dangerous drug-associated phenomena in the older adult such as bleedings or falls. Physicians should consider drug-associated origins of symptoms in older adults with an increased risk for serious health problems.
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Prevalence of a First-Degree Relative With Colorectal Cancer and Uptake of Screening Among Persons 40 to 54 Years Old. Clin Gastroenterol Hepatol 2020; 18:2535-2543.e3. [PMID: 31809916 DOI: 10.1016/j.cgh.2019.11.044] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 11/14/2019] [Accepted: 11/22/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS People with a first-degree relative with colorectal cancer (CRC) are recommended to start CRC screening at age 40. However, there is limited information on how many people in different age groups have a known family history of CRC and how many of them have had a colonoscopy. METHODS We set up a multicenter, cross-sectional, population-based study in Germany to determine what proportions of persons in age groups from 40 to 54 years old have a known family history of CRC. We invited 160,000 persons to participate in an online survey from 2015 through 2016. We investigated what proportions of persons in each age group reported a family history of CRC and what proportions of persons underwent a colonoscopy examination using descriptive statistics and multiple logistic regression models. RESULTS Of 28,711 responders to the online questionnaire (8428 were age 40-44 years, 9879 were age 45-49 years, and 10,404 were age 50-54 years), 2705 stated that they had a first-degree relative with CRC (9.4%). The prevalence of a first-degree relative with CRC increased with age: 7.5%, 9.6%, and 10.9% for people 40 to 44 years old, 45 to 49 years old, and 50 to 54 years old, respectively. The prevalence of a first-degree relative who received a diagnosis of CRC at age 70 years or older increased steadily with each age group. Although a greater proportion of people with a family history of CRC had undergone a colonoscopy examination (54.5%) than people without a family history of CRC (25.7%; P < .0001), large proportions of people within this risk group were not in compliance with the guidelines (54.8%, 47.6%, and 38.6% for ages 40-44 y, 45-49 y, and 50-54 y, respectively). CONCLUSIONS One in 10 persons in Germany age 40 to 54 years old has a first-degree relative with CRC. Guidelines recommend initiation of screening at ages 40 to 45 years for people with a family history, yet at this age many people do not have a family history of CRC yet, and almost half of persons 40 to 54 years old with a family history of CRC have not yet received a screening colonoscopy.
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Personalising drug safety—results from the multi-centre prospective observational study on Adverse Drug Reactions in Emergency Departments (ADRED). Eur J Clin Pharmacol 2019; 76:439-448. [DOI: 10.1007/s00228-019-02797-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 11/12/2019] [Indexed: 12/14/2022]
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Study protocol of the RaPS study: novel risk adapted prevention strategies for people with a family history of colorectal cancer. BMC Cancer 2018; 18:720. [PMID: 29976178 PMCID: PMC6034214 DOI: 10.1186/s12885-018-4646-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 06/28/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND People aged 40-60 years with a family history (FH) of colorectal cancer (CRC) in 1st degree relatives (FDRs) have a 2- to 4-fold increased risk of CRC compared to the average risk population. Therefore, experts recommend starting CRC screening earlier for this high-risk group. However, information on prevalence of relevant colonoscopic findings in this group is sparse, and no risk adapted screening offers are implemented in the German health care system. For example, screening colonoscopy is uniformly offered from age 55 on, regardless of family history. Thus, we initiated a multicenter epidemiological study - the RaPS study (Risk adapted prevention strategies for colorectal cancer) - with the following aims: to determine the prevalence of having a FH of CRC in FDR in the German population aged 40-54 years; to investigate the prevalence of colorectal neoplasms among people with a FDR; and to develop risk-adapted prevention strategies for this high-risk group based on the collected information. METHODS/DESIGN A random sample of 160.000 persons from the general population aged 40-54 years from the catchment areas of three study centers in Germany (Dresden, Munich and Stuttgart) are contacted to assess FH of CRC by an online-questionnaire. Those with a FH of CRC in FDRs are invited to the study centers for individual consultation regarding CRC prevention. Participants are asked to donate blood and stool samples and medical records of colonoscopies will be obtained. Prevalence of CRC and its precursors will be evaluated. Furthermore, genetic, epigenetic and proteomic biomarkers in blood and microbiomic biomarkers in stool will be investigated. Risk markers and their eligibility for risk adapted screening offers will be examined. DISCUSSION This study will provide data on the prevalence of colorectal neoplasms among persons with a FH of CRC in the age group 40-54 years, which will enable us to derive evidence based screening strategies for this high-risk group. TRIAL REGISTRATION This trial was registered retrospectively in the German Clinical Trials Register (DRKS) on 29th of December 2016: German Clinical Trials Register DRKS-ID: DRKS00007842 .
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Genetic polymorphism of cytochrome P450 2D6 determines oestrogen receptor activity of the major infertility drug clomiphene via its active metabolites. Hum Mol Genet 2011; 21:1145-54. [DOI: 10.1093/hmg/ddr543] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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The Impact of Thyroid Disease on the Regulation, Expression, and Function of ABCB1 (MDR1/P Glycoprotein) and Consequences for the Disposition of Digoxin. Clin Pharmacol Ther 2010; 88:685-94. [DOI: 10.1038/clpt.2010.176] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Propafenone for the Prevention of Atrial Tachyarrhythmias After Cardiac Surgery: A Randomized, Double-blind Placebo-controlled Trial. Clin Pharmacol Ther 2008; 84:104-10. [DOI: 10.1038/sj.clpt.6100473] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Increased??Absorption??of??Digoxin from??the??Human??Jejunum Due??to??Inhibition??of??Intestinal Transporter-Mediated Efflux. Clin Pharmacokinet 2007; 46:777-85. [PMID: 17713975 DOI: 10.2165/00003088-200746090-00005] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
BACKGROUND AND OBJECTIVES The contribution of transport in the small intestine by the apically located efflux pump P-glycoprotein to variable drug absorption in humans is still poorly understood. We therefore investigated whether inhibition of intestinal P-glycoprotein-mediated efflux by quinidine leads to increased absorption of the P-glycoprotein substrate digoxin. METHODS Using a multilumen perfusion catheter, we investigated the impact of P-glycoprotein inhibition on absorption of two compounds: the P-glycoprotein substrate digoxin and the marker for passive transcellular absorption antipyrine. Two 20cm adjacent jejunal segments were isolated with the multilumen perfusion catheter in seven healthy subjects. Unlabelled and deuterated digoxin and antipyrine, respectively, were simultaneously infused into either of the intestinal segments. One of the segments was additionally perfused with the P-glycoprotein inhibitor quinidine. Intestinal perfusates were collected for 3 hours, and drug concentrations were determined in the intestinal perfusates, plasma and urine. RESULTS Quinidine did not affect the disposition of antipyrine. In contrast, coadministration of quinidine into one jejunal segment caused a considerable increase in the amount of digoxin absorbed from this segment compared with the absorption from the other quinidine-free segment (22.3 +/- 8.9% vs 55.8 +/- 21.2% of the dose; p < 0.05). Accordingly, the area under the plasma concentration-time curve and the maximum plasma concentration of digoxin were considerably higher when luminal quinidine was coadministered (p < 0.05 and p < 0.001, respectively). Differences in digoxin absorption from the two intestinal segments were also reflected by pronounced differences in urinary digoxin elimination (5.5 +/- 3.3% vs 19.2 +/- 8.1% of the dose; p < 0.01). CONCLUSIONS P-glycoprotein inhibition in enterocytes increases systemic exposure of orally administered drugs that are P-glycoprotein substrates. These data highlight the importance of the small intestine as an active barrier against xenobiotics.
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Effect of acute hyperhomocysteinemia on methylation potential of erythrocytes and on DNA methylation of lymphocytes in healthy male volunteers. Am J Physiol Renal Physiol 2005; 289:F786-92. [PMID: 15855656 DOI: 10.1152/ajprenal.00465.2004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Homocysteine is a precursor of S-adenosylmethionine (AdoMet) and a metabolite of S-adenosylhomocysteine (AdoHcy). The ratio of AdoMet to AdoHcy, defined as the methylation potential (MP), indicates the flow of methyl groups within the cells. Chronic elevations of total homocysteine (tHcy) in plasma correlate with increased AdoHcy concentrations, decreased MP, and impaired DNA methylation. However, the influence of acute hyperhomocysteinemia on MP is unknown. We induced acute hyperhomocysteinemia in 14 healthy volunteers by oral administration of l-homocysteine (65.1 μmol/kg body wt) in an open, randomized, placebo-controlled two-period crossover study. The kinetics of tHcy in blood and urine, MP in blood, and global DNA methylation in lymphocytes were studied systematically during 48 h. Plasma tHcy concentrations reached a peak at 34 ± 11 min after an oral load with l-homocysteine and decreased with a half-life of 257 ± 41 min (means ± SD). Only 2.3% of the homocysteine dose were recovered in urine. AdoHcy concentrations and MP in whole blood and erythrocytes were not affected by the oral homocysteine load. Furthermore, global DNA methylation in lymphocytes did not change under these conditions. We found no difference between the genotypes of 5,10-methylenetetrahydrofolate reductase in response to the homocysteine load. However, AdoMet content in erythrocytes was significantly higher in the C677T carriers (CT; n = 7) compared with the CC genotype ( n = 7). Although chronic elevation of tHcy has been shown to affect MP and DNA methylation, acute elevation of plasma tHcy above 20 μmol/l for 8 h is not sufficient to change MP and to induce DNA hypomethylation in lymphocytes.
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