Do not use mercaptopurine if you are pregnant. It could harm the unborn baby. You should not use mercaptopurine if you are allergic to it, or if you have ever used mercaptopurine or thioguanine (Tabloid) and they were not effective in treating your condition. Some people using mercaptopurine have developed a rare fast-growing type of lymphoma (cancer). This condition affects the liver, spleen, and bone marrow, and it can be fatal. This has occurred mainly in teenagers and young adults using mercaptopurine or similar medicines to treat Crohns disease or ulcerative colitis. Call your doctor at once if you have any of the following symptoms: fever, night sweats, itching, loss of appetite, weight loss, tiredness, feeling full after eating only a small amount, pain in your upper stomach that may spread to your shoulder, nausea, easy bruising or bleeding, pale skin, feeling light-headed or short of breath, rapid heart rate, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes). ...

On April 28, 2014, the U.S. Food and Drug Administration approved a 20 mg/mL oral suspension of mercaptopurine (Purixan) indicated for the treatment of patients with acute lymphoblastic leukemia (ALL) as part of a combination regimen. Successive clinical trials have demonstrated that mercaptopurine contributes to successful maintenance therapy and improved survival of patients with ALL.. This approval was based on a clinical pharmacology study that assessed the bioequivalence of mercaptopurine tablets with that of mercaptopurine oral suspension in a healthy adult population.. New Formulation. The drug was originally approved in 1953 and has been commercially available as a 50-mg tablet. However, body surface area dosing and dose adjustments are not easily accomplished with the 50-mg tablet, and tablets are not an ideal dosage form of medication for children less than 6 years old. Ad hoc local formulations compounded in pharmacies are commonly used, and 50-mg tablets are often split to provide ...

TY - JOUR. T1 - Intermittent Granulocyte and Monocyte Apheresis Versus Mercaptopurine for Maintaining Remission of Ulcerative Colitis. T2 - A Pilot Study. AU - Sakuraba, Atsushi. AU - Sato, Toshiro. AU - Morohoshi, Yuichi. AU - Matsuoka, Katsuyoshi. AU - Okamoto, Susumu. AU - Inoue, Nagamu. AU - Takaishi, Hiromasa. AU - Ogata, Haruhiko. AU - Iwao, Yasushi. AU - Hibi, Toshifumi. PY - 2012/6. Y1 - 2012/6. N2 - The effect of granulocyte and monocyte adsorption apheresis (GMA) on prevention of relapse of ulcerative colitis (UC) is not clear. This was a pilot open-labeled, prospective, randomized, unblinded study to compare the tolerability and efficacy of intermittent GMA (once every 2weeks) with mercaptopurine to maintain remission of UC. Twenty-one patients with UC, who had achieved remission by induction therapies were randomly assigned to receive either intermittent GMA (N=10) or oral mercaptopurine (0.5mg/kg per day; N=11). The study period was 24months. The rate of the patients maintaining ...

Several published studies indicate that patients with reduced TPMT or NUDT15 activity receiving usual doses of mercaptopurine, accumulate excessive cellular concentrations of active 6-TGNs, and are at higher risk for severe myelosuppression. In a study of 1028 children with ALL, the approximate tolerated mercaptopurine dosage for patients with TPMT and/or NUDT15 deficiency on mercaptopurine maintenance therapy (as a percentage of the planned dosage) was as follows: heterozygous for either TPMT or NUDT15, 50-90%; heterozygous for both TPMT and NUDT15, 30-50%; homozygous for either TPMT or NUDT15, 5-10%. Approximately 0.3% (1:300) of patients of European or African ancestry have two loss-of-function alleles of the TPMT gene and have little or no TPMT activity (homozygous deficient or poor metabolizers), and approximately 10% of patients have one loss-of-function TPMT allele leading to intermediate TPMT activity (heterozygous deficient or intermediate metabolizers). The TPMT*2, TPMT*3A, and TPMT*3C ...

Azathioprine and 6-mercaptopurine (AZA/6MP) are effective immunosuppressives commonly used for the treatment of inflammatory bowel disease (IBD). The mercaptopurine metabolites, 6-thioguanine (6TG) and 6-methylmercaptopurine ...

Mercaptopurine is used to treat acute lymphoblastic or lymphocytic leukemia. Mercaptopurine is sometimes given with other cancer medications. Mercaptopurine may also be used for purposes not listed in this medication guide.

Buy Mercaptopurine with no prescription online from EU. Purchase Lowest Price International Pharmacy. Order Discount Mercaptopurine (Generic) Drug to Europe, France, Germany, Spain, Italy, European Union. Save euro!

PRIMARY OBJECTIVES:. I. Determine the impact of interventions proposed in intervention program (IP) versus (vs.) education alone (EDU) on adherence to oral 6MP (mercaptopurine) in children with acute lymphoblastic leukemia (ALL). Adherence will be measured by: i) Medication Event Monitoring Systems (MEMS) (primary measure of adherence to oral 6MP, providing real-time data; ii) red cell thioguanine nucleotide (TGN) levels (providing data on chronic, systemic 6MP exposure).. SECONDARY OBJECTIVES:. I. Examine the modifying effect of sociodemographic and psychosocial variables, and the mediating effect of health beliefs/ knowledge on change in adherence with intervention.. II. Determine impact of IP vs. EDU on risk of relapse of ALL.. OUTLINE: Patients are randomized to 1 of 2 intervention arms.. ARM I: Patients receive the Patients Supply Kit containing an electronic pill monitoring system, a MEMS? medication bottle with TrackCap? with standard resistant cap, and written instructions for the ...

Thiopurine methyltransferase (TPMT) deficiency is a condition in which patients treated with standard doses of azathioprine (AZA, Imuran), 6-mercaptopurine (6-MP, Purinethol), or 6-thioguanine (6-TG, Thioguanine Tabloid) may develop life-threatening myelosuppression or severe hematopoietic toxicity. The metabolic conversion of AZA, 6-MP, or 6-TG to purine nucleotides and the subsequent incorporation of these nucleotides into DNA play an important role in both the therapeutic efficacy and the toxicity of these drugs. A competitive catabolic route for the metabolism of thiopurines is catalyzed by the TPMT enzyme, which inactivates them by thiomethylation. A balance must be established between these competing metabolic pathways so that: 1) sufficient amounts of drug are converted to the nucleotide to act as an antimetabolite and 2) the antimetabolite levels do not become so high as to cause potentially lethal bone marrow suppression.. TPMT deficiency is an autosomal recessive condition with an ...

The evolution of perianal lesions during treatment was analyzed retrospectively. The team considered patients who had a clear anatomic improvement and who did not develop any perianal complications as responders.. The team found that after 3 years, the cumulative probabilities of remaining free of perianal complications and achieving a clear anatomic improvement were 0.47 and 0.4, respectively. They determined that 29% of patients were responders to azathioprine or 6-mercaptopurine therapy. The doctors identified the absence of fistula, duration of perianal disease shorter than 22 months, and age ≥40 years at inclusion as factors associated with response to therapy. There was no correlation between the response of perianal lesions and the achievement of intestinal remission with azathioprine or 6-mercaptopurine.. Dr Thierry Lecomtes team concluded, One-third of patients with perianal lesions of Crohns disease demonstrated a clear improvement during azathioprine or 6-mercaptopurine therapy. ...

The therapeutic role of 6-mercaptopurine (6-MP) and azathioprine (AZA) remains controversial due to their perceived relatively slow-acting effect and adverse effects. An updated meta-analysis was performed to evaluate the efficacy of these agents for the maintenance of remission in quiescent Crohns disease. To assess the efficacy of AZA and 6-MP for maintenance of remission in quiescent Crohns disease. We searched MEDLINE, EMBASE, and the Cochrane Library from inception to June 30, 2015. Randomized controlled trials of oral azathioprine or 6-mercaptopurine compared to placebo or active therapy involving adult patients (, 18 years) with quiescent Crohns disease were considered for inclusion. Patients with surgically-induced remission were excluded. At least two authors independently extracted data and assessed study quality using the Cochrane risk of bias tool. For dichotomous outcomes, we calculated the risk ratio (RR) and corresponding 95% confidence interval (CI). The primary outcomes was ...

The following drug interactions were observed in some patients undergoing treatment with oral allopurinol. Although the pattern of use for oral allopurinol includes longer term therapy, particularly for gout and renal calculi, the experience gained may be relevant.. Mercaptopurine/Azathioprine: Allopurinol inhibits the enzymatic oxidation of mercaptopurine and azathioprine to 6-thiouric acid. This oxidation, which is catalyzed by xanthine oxidase, inactivates mercaptopurine. In patients receiving mercaptopurine (Purinethol) or azathioprine (Imuran), the concomitant administration of 300-600 mg of allopurinol per day will require a reduction in dose to approximately one-third to one-fourth of the usual dose of mercaptopurine or azathioprine. Subsequent adjustment of doses of mercaptopurine or azathioprine should be made on the basis of therapeutic response and the appearance of toxic effects.. Dicumarol: It has been reported that allopurinol prolongs the half-life of the anticoagulant, dicumarol. ...

Introduction: 6-Mercaptopurine (6MP) is an important chemotherapeutic drug in the conventional treatment of childhood acute lymphoblastic leukemia (ALL). It is catabolized to 6-thiouric acid (6TUA) through 8-hydroxo-6-mercaptopurine (8OH6MP) or 6-thioxanthine (6TX) intermediates. Methods: High-performance liquid chromatography (HPLC) is usually used to determine the contents of therapeutic drugs, metabolites and other important biomedical analytes in biological samples. In the present study, the multivariate calibration methods, partial least squares (PLS-1) and principle component regression (PCR) have been developed and validated for the simultaneous determination of 6MP and its oxidative metabolites (6TUA, 8OH6MP and 6TX) without analyte separation in spiked human plasma. Mixtures of 6MP, 8-8OH6MP, 6TX and 6TUA have been resolved by PLS-1 and PCR to their UV spectra. Results: Recoveries (%) obtained for 6MP, 8-8OH6MP, 6TX and 6TUA were 94.5-97.5, 96.6-103.3, 95.1-96.9 and 93.4-95.8, respectively,

6-mercaptopurine is given by mouth and intravenously (IV) to treat cancer. Find 6-mercaptopurine side effects, allergic reactions, and more.

Buy Mercaptopurine 50mg online without prescription in USA, Canada, Australia, UK and Europe. Fast order delivery. Worldwide shipping. FDA approved RX online pharmacy.

The thiopurine drugs are purine antimetabolites that are useful in the treatment of acute lymphoblastic leukemia, autoimmune disorders (e.g., Crohn disease, rheumatoid arthritis), and organ transplant recipients. The thiopurine drugs, 6-mercaptopurine (6-MP), 6-thioguanine (6-TG), and azathioprine (AZA) are prodrugs that require intracellular activation to 6-thioguanine nucleotides (6-TGN). This activation is catalyzed by multiple enzymes. The cytotoxic effects of thiopurine drugs are achieved mainly through incorporation of 6-TGN into DNA and RNA. The pathway that leads to synthesis of active cytotoxic 6-TGN is in competition with inactivation pathways catalyzed by thiopurine methyltransferase (TPMT). Evaluation of this pathway is important because the level of 6-TGN measured in red blood cells have been correlated with both thiopurine therapeutic efficacy and toxicity such as myelosuppression.. TPMT activity is inherited as a monogenic codominant trait, and variable TPMT activity is associated ...

The discovery and implementation of thiopurine methyltransferase (TPMT) pharmacogenetics has been a success story and has reduced the suffering from serious adverse reactions during thiopurine treatment of childhood leukaemia and inflammatory bowel disease. This MiniReview summarizes four studies included in Dr Zimdahl Kahlins doctoral thesis as well as the current knowledge

Medical information for Mercaptopurine on Pediatric Oncall including Mechanism, Indication, Contraindications, Dosing, Adverse Effect, Interaction, Renal Dose, Hepatic Dose.

Thiopurine methyltransferase (TPMT) is an enzyme that breaks down a class of drugs called thiopurines. TPMT tests are used to identify people at risk of developing severe side effects from thiopurine treatment.

Measurement of TPMT activity is encouraged prior to commencing the treatment of patients with thiopurine drugs such as azathioprine, 6-mercaptopurine and 6-thioguanine. Patients with low activity (10% prevalence) or especially absent activity (prevalence 0.3%) are at a heightened risk of drug-induced bone marrow toxicity due to accumulation of the unmetabolised drug. Reuther et al. found that about 5% of all thiopurine therapies will fail due to toxicity. This intolerant group could be anticipated by routine measurement of TPMT activity. There appears to be a great deal of variation in TPMT mutation, with ethnic differences in mutation types accounting for variable responses to 6MP.[9][12] Genetic variants of TPMT have also been associated with cisplatin-induced ototoxicity in children.[13] TPMT is now listed as a pharmacogenomic biomarker for adverse drug reactions to cisplatin by the FDA.[14] ...

1. The transport of 6-thioguanine and 6-mercaptopurine has been studied with isolated jejunal loops of mouse small intestine. H.p.l.c. was used to identify and quantify the thiopurines and their metabolites in the serosal secretions. 2. When the lumen of the intestinal loops contained either 6-thioguanine or 6-mercaptopurine at a concentration of 1 mmol/l, the concentration of unmetabolized drug in the serosal secretions reached a maximum of 0.13 ± 0.02 mmol/l (mean ± sem ). 3. Analysis of the serosal secretions from the perfusions with either of the drugs revealed the appearance of an unknown compound which had the characteristics of a thiopurine and the same time course of appearance as the unmetabolized drug. Thus 6-thioguanine and 6-mercaptopurine are significantly metabolized during absorption in mouse intestine. 4. The unknown compound was identified as 6-thiouric acid, and with 1 mmol/l 6-thioguanine or 6-mercaptopurine in the lumen the concentration of this metabolite in the serosal ...

Approximately 0.3% of the population has a profound genetic deficiency of thiopurine methyltransferase, the major route for detoxification of thiopurines used in immunosuppression and oncology.. These patients develop severe marrow suppression if given usual doses of a thiopurine drug or prodrug. The condition is inherited as an autosomal recessive trait, and about 11% of the population are carriers.. Carriers may also show decreased tolerance to the drugs, although not as severely as the severely deficient patients.. ...

The anticancer drug 6-mercaptopurine (6-MP) inhibits purine synthesis and acts as an antiproliferative agent by interfering with protein, RNA and DNA activity and promoting apoptosis. modifies human being leukemic Capital t cells rate of metabolism with potential antiproliferative results. purine activity [1C6, 10]which can be important for lymphocyte expansion because these cells rely even more on path than on the repair path [5, 16, 17]. 6-MP may inhibit biosynthesis of ATP PX-866 and GTP PX-866 [18] also. In addition, latest proof shows that 6-MP prevents the phosphatidylinositol 3 kinase (PI3E) / mammalian focus on of rapamycin (mTOR) signaling path [8], recommending that these medicines might get in the way with metabolic checkpoints and effect metabolic reprogramming in regular Capital t cells and tumor [19]. In range with its feasible part in cell metabolic reprogramming, 6-MP manages the activity of people of the orphan nuclear receptor NR4A family members, which functions as crucial ...

Purixan (mercaptopurine) is used to treat acute lymphoblastic leukemia. Includes Purixan side effects, interactions and indications.

1 Answer - Posted in: immunosuppression, autoimmune hepatitis - Answer: Hello MbSunny54 I dont know anything about Mercaptopurine but a quick ...

Gentaur molecular products has all kinds of products like :BioBasic , BioBasic \ 6_Mercaptopurine \ M714163 for more molecular products just contact us

Autori: A. V. Szeghalmi, L. Leopold, S. Pînzaru , V. Chis, I. Silaghi-Dumitrescu, M. Schmitt, J. Popp, W. Kiefer. Editorial: J. Mol. Str., 735-736, p.103-113, 2005.. Rezumat:. Cuvinte cheie: DFT, 6-mercaptopurine, Raman spectroscopy, SERS. ...

Buy Purinethol (mercaptopurine) 50mg online without prescription in USA, Canada, Australia, UK and Europe. Fast order delivery. Worldwide shipping. FDA approved RX online pharmacy.

6-mercaptopurine monohydrate testing. Laboratory testing for CAS number 6112-76-1. . This chemical is light yellow crystalline powder

The best-studied example of genetic variation within a DME and its effect on toxicity is the interaction between variants in thiopurine methyltransferase (TPMT) and toxicity with the thiopurine antimetabolites 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG). 6-MP is used as an immunosuppressant for some nonmalignant conditions, such as inflammatory bowel diseases (12, 13), and is one of the backbones of treatment in the most frequent pediatric malignancy, acute lymphoblastic leukemia [ALL (14)]. The thiopurines are prodrugs that are converted by multiple enzymes into thioguanine nucleotides (TGN), which are then incorporated into DNA. Inactivation of TGN occurs by 2 main mechanisms: oxidation by xanthine oxidase and methylation by TPMT. Xanthine oxidase activity is negligible in hematopoietic tissues, so these cells rely on TPMT for TGN inactivation (15).. Struck by the wide interpatient variability in both response and toxicity observed in patients treated with 6-MP, Weinshilboum and Sladek ...

Thiopurine methyltransferase (TPMT) testing is important in the detection of individuals with altered TPMT activity who are at risk for severe hematopoietic toxicity when taking thiopurine medications (6-mercaptopurine, azathioprine, and 6-thioguanine). This webinar will outline the different tests to detect patients who are at risk for thiopurine-related toxicity and the advantages of each test. It is intended to educate clinicians and increase their confidence when treating patients with thiopurine medications.. ...

Abstract. Background: We noted that rare patients with acute lymphoblastic leukemia (ALL) who are intolerant to oral mercaptopurine (6MP) and methotrexate (MTX

An antimetabolite antineoplastic agent with immunosuppressant properties. It interferes with nucleic acid synthesis by inhibiting purine metabolism and is used, usually in combination with other drugs, in the treatment of or in remission maintenance programs for leukemia. [PubChem]

BACKGROUND: The activity of the human enzyme thiopurine methyltransferase (TPMT) varies greatly between individuals because of genetic polymorphism. TPMT is involved in the detoxification and activation of thiopurines such as 6-mercaptopurine, 6-thioguanine, and azathioprine. These drugs are used in the treatment of acute lymphoblastic leukemia and inflammatory bowel disease. A total of 29 sequence variants have been identified so far in the TPMT gene. However, most of these variants are rare and not fully characterized. METHODS AND RESULTS: In this study, we describe the identification and characterization of a novel TPMT sequence variant, originally found in a Swedish man of Italian origin. Sequencing of the variable number tandem repeats region of the TPMT promoter and exons III-X revealed a T-to-C transition at nucleotide 611, causing an amino acid substitution from isoleucine to threonine at amino acid 204, positioned in an α-helix, approximately 16 Å from the active site. This new ...

Acute lymphoblastic leukemia (ALL) is responsible for almost a third of all childhood cancers and can be cured with combination chemotherapy alone [

Mercaptopurine is one of a large series of purine analogues which interfere with nucleic acid biosynthesis and has been found active against human leukemias. It is an analogue of the purine bases adenine and hypoxanthine. It is not known exactly which of any one or more of the biochemical effects of mercaptopurine and its metabolites are directly or predominantly responsible for cell death ...

PRIMARY OBJECTIVES: I. To evaluate the 3-year survival rate in elderly patients with newly diagnosed Philadelphia (Ph)-negative acute

The in vitro transformation responses of lymphocytes to stimulation with phytohemagglutinin (PHA) and smallpox vaccine (vaccinia) were studied in cells from 20 patients with ocular and malignant diseases receiving chemotherapy. The transformation of lymphocytes to lymphoblast-like cells was reduced from 71% in the pretreatment PHA-stimulated cultures to 1.5% during therapy. The response to vaccinia was reduced from 12% before therapy to 0% during therapy. The mitotic indices fell from 1.5% (PHA) and 1.2% (vaccinia) to 0% for each during therapy.. Intensive combination therapy with parenteral 6-mercaptopurine and methotrexate, with or without prednisolone completely abolished transformation after 3 days of treatment. Substantial recovery occurred within 3 days after the end of therapy. Nontoxic therapy with methotrexate or 6-mercaptopurine which did not induce leukopenia took 2-5 weeks to cause maximum suppression.. The abnormality seemed due to intrinsic damage to the lymphocytes and not to ...

Citation: Foureman, P., Mason, J.M., Valencia, R., Zimmering, S. Chemical Mutagenesis Testing in Drosophila. X. Results of 70 coded compounds tested for the National Toxicology Program. Environ. Molec. Mutagen. Vol. 23 (1994) 208- ...

Definition : Molecular assay reagents intended to identify mutations in the tumor protein p53 (TP53) gene, located at chromosome 17p13.1, which encodes for a protein that acts as a tumor suppressor and induces cellular apoptosis. This inherited genetic mutation and/or genetic anomalies have been identified in patients with many types of cancers.. Entry Terms : 6-Mercaptopurine Inactivation Gene Mutation Reagents , Thiopurine Methyltransferase High Activity Gene Mutation Reagents , TPMT Gene Mutation Detection Reagents , Reagents, Molecular Assay, Gene Anomaly, Mutation, TPMT. UMDC code : 24995 ...

A big warm fruit scone came with an individual jar of strawberry jam, butter and a small bowl of clotted cream. Keep in mind that a small classroom can still be a great learning environment if you make the appropriate preparations. The putative mother of all the neo-folkists who have appeared for two decades, chan marshall has always had the grace to salute his predecessors and to quote his rise. Pero si la persona trabajadora cumple con prestar un servicio a la hora y de la forma que desee, sin estar sujeto a sanciones disciplinarias, si los errores cometidos corren por su cuenta, entonces es un contrato por servicios profesionales, y no hay contrato de trabajo. The main task of the checkpoint in g2 phase is to block cell entry into mitosis in the event of an anomaly in the genetic material. They involved maximum application of theoretical findings acquired in practice under socialism. An algorithm with the proposed management of thiopurine treatment according to metabolite determination is ...

Biology Assignment Help, Maintenance therapy for leukemia, Maintenance Therapy A complete remission implies a clinical, haematological and bone marrow remission. For remission therapy drugs like, methotrexate cyclophospharnide and 6-mercaptopurine are used. Usually a combination of two drugs is employ

Seizure-associated, aberrant neurogenesis in full-grown rats characterized with retrovirus-mediated chamber labelingExamples of students who may for an IHP are students with asthma, bad allergies, long-standing conditions such as type 1 diabetes, diplomate disabilities, attention deficit/hyperactivity tangle, and medication needsAdditionally, it allows unwasteful manual mining and uprooting of semantic entities not later than implementing a text machine [214]Provender intelligence about the following garden-variety medications tolerant of to curb the murrain: · 5-Aminosalicylates (5-ASA): hardened to restrain decline (in the main toughened in ulcerative colitis) · Antibiotics (all things considered metronidazole and ciprofloxacin): typically used in children who secure perianal Crohn ailment · Immunomodulators (usually 6-mercaptopurine [6-MP] or azathioprine): used to help maintain remission [url=https://www.hop-play.com/directive/cheap-online-kamagra-effervescent-no-rx/]kamagra effervescent ...

TY - JOUR. T1 - Farmacogenetica en bloedspiegelbepalingen bij thiopurines. AU - Al Hadithy, Asmar F.Y.. AU - De Boer, N. K.H.. AU - Derijks, L. J.J.. AU - Mulder, C. J.J.. AU - Brouwers, J. R.B.J.. PY - 2004/12/24. Y1 - 2004/12/24. UR - http://www.scopus.com/inward/record.url?scp=11444261405&partnerID=8YFLogxK. M3 - Article. AN - SCOPUS:11444261405. VL - 139. SP - 1744. EP - 1747. JO - Pharmaceutisch Weekblad. JF - Pharmaceutisch Weekblad. SN - 0031-6911. IS - 52-53. ER - ...

Use during the 30 days before Screening (or 5 half-lives, whichever is longer) or use during the Screening period of any medications that may interfere with the study with as immunosuppressive or immunodulatory drugs (including azathioprine, 6-mercaptopurine, methotrexate, tacrolimus, anti-TNF, anti-IL-5, anti-IL-5 receptor, dupilumab, anti-IgE antibodies, omalizumab) or systemic corticosteroids with a daily dose ,10mg of prednisone or equivalent ...

I have been on Humira for almost 2 years. I still have inflammation so the doc wants me to take mercaptopurine along with the Hurmira. I am hesitant due...

Canadian Pharmacy: Fincar For Sale - Get quality medication online! The lowest prices on the Net mercaptopurine! No prescription required fluconazole 200 mg for dogs.

collapsCat options: Array ( [title] => Article Categories [showPostCount] => 0 [inExclude] => exclude [inExcludeCats] => default-title,uncategorized,featured-articles,180,1651,ce-accessories [showPosts] => 0 [showPages] => 0 [linkToCat] => 1 [olderThan] => 0 [excludeAll] => 0 [catSortOrder] => ASC [catSort] => catName [postSortOrder] => ASC [postSort] => postTitle [expand] => 4 [defaultExpand] => [debug] => 1 [postTitleLength] => 0 [catfeed] => none [taxonomy] => category [post_type] => post [postDateAppend] => after [postDateFormat] => m/d [showPostDate] => 0 [useCookies] => 0 [postsBeforeCats] => 0 [expandCatPost] => 1 [showEmptyCat] => 1 [showTopLevel] => 1 [useAjax] => 0 [customExpand] => [customCollapse] => [style] => kubrick [accordion] => 1 [title_link] => [addMisc] => 0 [addMiscTitle] => [number] => 2 [includeCatArray] => Array ( ) [expandSym] => [collapseSym] => ) postsToExclude: Array ( ) CATEGORY QUERY RESULTS Array ( [0] => WP_Term Object ( [term_id] => 165 [name] => 2.o™ HPLC ...

1. The formation of adenosine 5-phosphate, guanosine 5-phosphate and inosine 5-phosphate from [8-(14)C]adenine, [8-(14)C]guanine and [8-(14)C]hypoxanthine respectively in the presence of 5-phosphoribosyl pyrophosphate and an extract from Ehrlich ascites-tumour cells was assayed by a method involving liquid-scintillation counting of the radioactive nucleotides on diethylaminoethylcellulose paper. The results obtained with guanine were confirmed by a spectrophotometric assay which was also used to assay the conversion of 6-mercaptopurine and 5-phosphoribosyl pyrophosphate into 6-thioinosine 5-phosphate in the presence of 6-mercaptopurine phosphoribosyltransferase from these cells. 2. At pH 7.8 and 25 degrees the Michaelis constants for adenine, guanine and hypoxanthine were 0.9 mum, 2.9 mum and 11.0 mum in the assay with radioactive purines; the Michaelis constant for guanine in the spectrophotometric assay was 2.6 mum. At pH 7.9 the Michaelis constant for 6-mercaptopurine was 10.9 mum. 3. 25 mum-6

This study examined thiopurine methyltransferase (TPMT) and the relationship to thioguanine nucleotides (TGN) and methylthioinosine monophosphate (meTIMP) in a large Swedish patient population. The current hypothesis is that the cytotoxic effects of thiopurine drugs are mediated by the incorporation of TGN into DNA. The authors assayed the TPMT activity in red blood cells from 1151 subjects and the concentrations of TGN (n = 602) and meTIMP (n = 593) from patients treated with thiopurine drugs. The TPMT frequency distribution in both adults and children showed some differences from what had been found in unselected general populations. Children had lower median TPMT activity than adults (12.0 versus 12.9 U/mL RBC, P < 0.001). Relative differences in both TGN formation [medians: normal TPMT, 1.3, intermediate TPMT, 3.3, low TPMT, 47.9 pmol/8 × 108 RBC per mg azathioprine (AZA), P < 0.001] and meTIMP formation (medians: normal TPMT, 13, intermediate TPMT, 7.3, low TPMT, 0 pmol/8 × 108 RBC per mg ...

The three thiopurine drugs azathioprine (AZA), 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG) are used to treat several diseases, including inflammatory bowel disease (IBD). They are pro-drugs and are believed to act through the formation of thioguanine nucleotides (TGNs). Other important metabolites are the methylthioinosine nucleotides (meTINs). These metabolites are active in the white blood cells (WBCs).Most patients respond well to the thiopurine drugs but up to a third have to modify or discontinue their treatment due to adverse events or a lack of therapeutic effects. This could be caused by inter-patient variability in the metabolism of the drugs. Therapeutic drug monitoring (TDM) of thiopurine nucleotides in red blood cells (RBCs) is used to guide treatment. Current routine assays measure the nucleotides after hydrolysation to nucleic bases and are therefore unable to distinguish between mono-, di-, and triphosphates. Recently it was shown that these assays failed to predict the ...

Thiopurine S-methyltransferase (TPMT) catalyzes the S-methylation of aromatic and heterocyclic sulfhydryl compounds including thiopurine drugs such as 6-mercaptopurine, 6-thioguanine and azathioprine. TPMT activity exhibits genetic variation and show

Genetics Home Reference : 25 Thiopurine S-methyltransferase (TPMT) deficiency is a condition characterized by significantly reduced activity of an enzyme that helps the body process drugs called thiopurines. These drugs, which include 6-thioguanine, 6-mercaptopurine, and azathioprine, inhibit (suppress) the bodys immune system. Thiopurine drugs are used to treat some autoimmune disorders, including Crohn disease and rheumatoid arthritis, which occur when the immune system malfunctions. These drugs are also used to treat several forms of cancer, particularly cancers of blood-forming tissue (leukemias) and cancers of immune system cells (lymphomas). Additionally, thiopurine drugs are used in organ transplant recipients to help prevent the immune system from attacking the transplanted organ. A potential complication of treatment with thiopurine drugs is damage to the bone marrow (hematopoietic toxicity). Although this complication can occur in anyone who takes these drugs, people with TPMT ...

Azathioprine has been in use for decades as an immunosuppressant treatment for various autoimmune diseases. It is a prodrug of mercaptopurine, a substance that is subsequently metabolised by several alternative pathways, one of which involves the enzyme thiopurine methyltransferase (TPMT). Some people have deficiency of TPMT because of genetic mutations. This has been widely said to occur in around 3 in 1,000 individuals;1 however, studies in recent years have suggested a prevalence of up to 6 in 1,000.2,3 These people are at great risk of developing severe, potentially life-threatening bone marrow toxicity when treated with conventional doses of azathioprine or mercaptopurine. It is possible to test patients for TPMT activity before starting treatment with these drugs. Here we review the evidence about such testing, and discuss whether it should be used for patients being considered for azathioprine therapy. ...

Why have I been started on this medicine? Azathioprine (AZAT) and mercaptopurine (MP) are two related medications used to control the immune defence system. Many inflammatory bowel disease (IBD) patients have been safely using them since the 1970s. Elion and Hitchings developed AZAT and MP in 1950s, going on to share the 1988 Nobel prize in Medicine. In Crohns and ulcerative colitis, the gastrointestinal immune system is often overactive. Decreasing this overactivity can help to prevent intestinal bleeding, loose motions, pain and other complications.. How long will I need to take it to feel better? These drugs usually work slowly. Results (ie. decreasing or getting off prednisone, good pain-relief or healing the bowel, fistula or abscess) happen usually by 2-6 months, so make sure to take your pills every day as directed and dont give up too early. Some get better faster (20% at 2 weeks) and others take longer (6 -12 months). AZAT/MP is usually given for up to 5 years and beyond if it is ...

0054] Other representative examples include 6-S-aminoacyloxymethyl mercaptopurine derivatives (Harada et al., Chem. Pharm. Bull. 43(10):793-6, 1995), 6-mercaptopurine (6-MP) (Kashida et al., Biol. Pharm. Bull. 18(11)1492-7, 1995), 7,8-polymethyleneimidazo-1,3,2-diazaphosphorines (Nilov et al., Mendeleev Commun. 2:67, 1995), azathioprine (Chifotides et al., J. Inorg. Biochem. 56(4):249-64, 1994), methyl-D-glucopyranoside mercaptopurine derivatives (Da Silva et al., Eur. J. Med. Chem. 29(2):149-52, 1994) and s-alkynyl mercaptopurine derivatives (Ratsino et al., Khim.-Farm. Zh. 15(8):65-7, 1981); indoline ring and a modified ornithine or glutamic acid-bearing methotrexate derivatives (Matsuoka et al., Chem. Pharm. Bull. 45(7):1146-1150, 1997), alkyl-substituted benzene ring C bearing methotrexate derivatives (Matsuoka et al., Chem. Pharm. Bull, 44(12):2287-2293, 1996), benzoxazine or benzothiazine moiety-bearing methotrexate derivatives (Matsuoka et al., J. Med. Chem. 40(1):105-111, 1997), ...

Azathioprine is well absorbed following oral administration. Maximum serum radioactivity occurs at 1 to 2 hours after oral 35S-azathioprine and decays with a half-life of 5 hours. This is not an estimate of the half-life of azathioprine itself, but is the decay rate for all 35S-containing metabolites of the drug. Because of extensive metabolism, only a fraction of the radioactivity is present as azathioprine. Usual doses produce blood levels of azathioprine, and of mercaptopurine derived from it, which are low (,1 mcg/mL). Blood levels are of little predictive value for therapy since the magnitude and duration of clinical effects correlate with thiopurine nucleotide levels in tissues rather than with plasma drug levels. Azathioprine and mercaptopurine are moderately bound to serum proteins (30%) and are partially dialyzable. (See OVERDOSAGE).. Azathioprine is metabolized to 6-mercaptopurine (6-MP). Both compounds are rapidly eliminated from blood and are oxidized or methylated in erythrocytes ...

I decided to pregnancy and mercaptopurine a significant part of this post to an useful description of the acidic foodstuffs because it is very important to understand their characteristics and also to be aware of the fundamental aspect of these foods that is crucial when aiming for a baby of a desired gender. Ive been having period cramps for about three days because of my upcoming interval. Although to an extent, pregnancy recognizing is totally regular and harmless in early being pregnant. By the end of this week its circulation is starting to function. As the second trimester comes to an finish, your baby is making his presence recognized - and your maternal instincts may be rising as properly. In a current study, teetotallers conceived more rapidly and had fewer miscarriages than even very light drinkers. Did you know… We have over 49 school courses that put together you to earn credit score by exam thats accepted by over 2,000 colleges and universities. Understanding the easy story of ...

TY - JOUR. T1 - Initiating Azathioprine for Crohns Disease. AU - Levesque, Barrett G.. AU - Loftus, Jr, Edward Vincent. PY - 2012/5. Y1 - 2012/5. N2 - Azathioprine (AZA) and 6-mercaptopurine are therapeutic options for patients with moderate to severe inflammatory Crohns disease. AZA has both a complex metabolism and potential for adverse events that can be clinically challenging. AZA has been shown to maintain remission and reduce corticosteroid use in patients with Crohns disease. There is heterogeneous thiopurine methyltransferase metabolism among patients, which has implications for clinical dosing and risk for adverse events. Routine thiopurine methyltransferase testing before the initiation of AZA will reduce early leukopenia and is mandatory to avoid potentially life-threatening myelotoxicity. Thiopurine metabolite assays may aid in the assessment of adherence and adverse events. Patients who do not respond to AZA therapy may benefit from the addition of biologic therapy or ...

Introduction Measuring azathioprine or mercaptopurine (AZA) metabolite levels 6-TGN and 6-MMPN allows identification of patients who are: 1. Non compliant with their medication, 2. On a sub-optimal doe, 3. On a supra-therapeutic dose, 4. Are preferentially metabolising azathioprine to methylated metabolites (6-MMPN:6-TGN ratio , 11).. Our own and others published data demonstrate that measuring metabolite levels in patients failing azathioprine therapy followed by appropriate changes in dosing and/or the addition of allopurinol (with 75% dose reduction in AZA) can result in clinical remission in the majority of patients 1. We report the outcome of the routine measurement of metabolite levels in patients treated with AZA who were in a clinical remission without side effects or abnormal liver function tests (LFTs).. ...

PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Thiopurines, including azathioprine, 6-mercaptopurine, and thioguanine, are medicines used to manage several different conditions and your genes can affect how well the drugs work. CPIC updates guidelines on how to best use these genetic results to support patient care and has published its current interpretations here.. Normal starting doses vary by race/ethnicity and treatment regimens. The higher frequency of TPMT variants in those with European and African backgrounds should be considered. If standard dose is below normal recommended dose, dose reduction might not be recommended for intermediate metabolizers.. ...

Result 64 individuals studied, median age 14 years. Underlying diagnoses were IBD (54/64) and other (10/64). 59 treated with AZA, 5 with 6-MP. 95 separate measurements were made. TPMT phenotype was measured in 51/64 patients,40/51 had normal phenotype, and 11/51 had heterozygous TPMT mutations. Initial 6-TGN levels were higher in heterozygotes (median levels 836 vs 328, p=0.001) at comparable doses of thiopurine (median 1.9 vs 2.2 mg/kg, p=0.11). On first measurement, only 30% patients had 6-TGN levels within therapeutic levels. 30% were subtherapeutic and 40% were supra-therapeutic. 9% had 6-TGN levels ,800. Toxicity occurred in 8 cases (9%). Leucopaenia (WBC,4) had a sensitivity of 12.5% in predicting supra-therapeutic 6-TGN levels. Concomitant use of 5-ASA did not significantly affect 6-TGN levels at comparable doses (median (6-TGN) 5-ASA 393 vs 451 no 5-ASA, p=0.26). In total, management was changed in 39 cases (41%). 6 cases of total non-compliance were exposed. 33/39 of these ...

This drug may make you feel generally unwell. This is not uncommon, as chemotherapy can affect healthy cells as well as cancer cells. Report any side effects. Continue your course of treatment even though you feel ill unless your doctor tells you to stop.. This medicine may increase your risk to bruise or bleed. Call your doctor or health care professional if you notice any unusual bleeding.. Call your doctor or health care professional for advice if you get a fever, chills or sore throat, or other symptoms of a cold or flu. Do not treat yourself. This drug decreases your bodys ability to fight infections. Try to avoid being around people who are sick.. This medicine can make you more sensitive to the sun. Keep out of the sun. If you cannot avoid being in the sun, wear protective clothing and use sunscreen. Do not use sun lamps or tanning beds/booths.. Talk to your doctor about your risk of cancer. You may be more at risk for certain types of cancers if you take this medicine.. Do not become ...

This drug may make you feel generally unwell. This is not uncommon, as chemotherapy can affect healthy cells as well as cancer cells. Report any side effects. Continue your course of treatment even though you feel ill unless your doctor tells you to stop.. Call your doctor or health care professional for advice if you get a fever, chills or sore throat, or other symptoms of a cold or flu. Do not treat yourself. This drug decreases your bodys ability to fight infections. Try to avoid being around people who are sick.. This medicine may increase your risk to bruise or bleed. Call your doctor or health care professional if you notice any unusual bleeding.. This medicine can make you more sensitive to the sun. Keep out of the sun. If you cannot avoid being in the sun, wear protective clothing and use sunscreen. Do not use sun lamps or tanning beds/booths.. Talk to your doctor about your risk of cancer. You may be more at risk for certain types of cancers if you take this medicine.. Do not become ...

This drug may make you feel generally unwell. This is not uncommon, as chemotherapy can affect healthy cells as well as cancer cells. Report any side effects. Continue your course of treatment even though you feel ill unless your doctor tells you to stop.. Call your doctor or health care professional for advice if you get a fever, chills or sore throat, or other symptoms of a cold or flu. Do not treat yourself. This drug decreases your bodys ability to fight infections. Try to avoid being around people who are sick.. This medicine may increase your risk to bruise or bleed. Call your doctor or health care professional if you notice any unusual bleeding.. This medicine can make you more sensitive to the sun. Keep out of the sun. If you cannot avoid being in the sun, wear protective clothing and use sunscreen. Do not use sun lamps or tanning beds/booths.. Talk to your doctor about your risk of cancer. You may be more at risk for certain types of cancers if you take this medicine.. Do not become ...

Doctors have discovered that patients with a particular genetic variation are four times more likely to develop pancreatitis if they are prescribed a widely used group of drugs.. Clinicians at the Royal Devon and Exeter NHS Foundation Trust and the University of Exeter Medical School have discovered that 17 per cent of patients who have two copies of a particular genetic marker are likely to go on to develop pancreatitis if they are prescribed thiopurine drugs. The drugs, which include azathioprine and mercaptopurine, are some of the most effective and most commonly used drugs to suppress the immune system in the treatment of Inflammatory Bowel Disease (IBD), rheumatoid arthritis and after some organ transplants.. It has long been recognised that about four per cent of patients who are prescribed these drugs for IBD go on to develop pancreatitis, an inflammation of the pancreas, which can be fatal. But in a study published in Nature Genetics, doctors have identified a group of patients whose ...

The research protocol extends for up to 3.5 months, during which the participant will attend 5 clinic visits at Shaare Zedek Medical Centre: screening visit, week 0, week 4, week 8 and week 12.. During the screening visit, all patients identified who meet the exclusion and inclusion criteria and who agree to participate in the study, will have their medical records reviewed for previous clinical or biochemical evidence of pancreatitis, both related, and unrelated to thiopurine use.. Patients will undergo a physical examination, baseline blood tests including measurement of lipase and/or amylase, liver biochemistry and fasting lipid profile. If not already tested, the patients TPMT activity will be tested. Participants will also have a baseline abdominal ultrasound to confirm normal anatomy and absence of cholelithiasis At week 0, if there are no clinical, biochemicals or ultrasound suggestions of pancreatitis, the participant will be commenced on an alternative thiopurine from what was used in ...

Multiple genotype tests can be performed on a single specimen after a single extraction. See Multiple Genotype Test List in Special Instructions for a list of tests that can be ordered together.. Submit only 1 of the following specimens:. Specimen Type: Whole blood. Container/Tube: Lavender top (EDTA). Specimen Volume: 3 mL. Collection Instructions:. 1. Invert several times to mix blood.. 2. Send specimen in original tube.. Specimen Stability Information: Ambient (preferred) 9 days/Refrigerated 30 days. Specimen Type: Saliva. Patient Preparation: Patient should not eat, drink smoke, or chew gum 30 minutes prior to collection.. Supplies: Saliva Swab Collection Kit (T786). Specimen Volume: One swab. Collection Instructions: Collect and send specimen per kit instructions.. Specimen Stability Information: Ambient 30 days. Specimen Type: DNA. Container/Tube: 2 mL screw top tube. Specimen Volume: 100 mcL. Collection Instructions:. 1. The preferred volume is 100 mcL at a concentration of 50 ...

Angiogene Pharmaceuticals was developing bioreductive prodrugs of 6-mercaptopurine (6-MP) or 6-thioguanine (6-TG) for the treatment of cancer. Tissue hypoxia is

Methylation of MP by TPMT is a critical step in thiopurine metabolism. It was first noted in the 1980s that differences in TPMT activity help account for the variability in tolerance to thiopurines. Rare and common genetic polymorphisms influence enzyme function resulting in a trimodal population distribution of activity. In Caucasians, complete TPMT deficiency occurs in 1 in 300 individuals. Carriers of a deficiency-associated allele (heterozygotes) have around 50% enzyme activity and occur at an approximate frequency of 1 in 10 of the population.10 The majority of cases of TPMT deficiency (∼95%) are associated with three alleles, TPMT*2, TPMT*3A and TPMT*3C.11 The frequency of these variants depends on ethnicity with TPMT*3A being more common in Caucasian populations.12 Individuals with complete TPMT deficiency who receive standard doses of AZA or MP are highly likely to develop severe and potentially fatal myelosuppression. There is a small case series of patients with IBD treated with ...

簡介 Azathiorine是thioguanine的衍生物，為類似purine的分子。此藥為prodrug，在吸收後，能夠被紅血球轉成主要的活性代謝物6-Mercaptopurine (6-MP)，進而發揮作用。 藥物代謝 (1) 此藥在腸道的吸收良好 (2) 為prodrug，能夠被紅血球代謝為主要活性代謝物6-MP (3) Azathioprine→45%會被尿液排除，55%被代謝為6-MP (4) 6-MP的代謝，則有兩個路徑 經由xanthine oxidase，氧化成6-thiouric ...

Definition of tioguanine in the Definitions.net dictionary. Meaning of tioguanine. What does tioguanine mean? Information and translations of tioguanine in the most comprehensive dictionary definitions resource on the web.

Detection of genetic polymorphisms in the Thiopurine S-methyltransferase gene for the prevention of dose-related toxicity during treatment with thiopurine drugs; including (if performed) any service described in item 65075. 1 or more tests Fee: $51.95 Benefit: 75% = $39.00 85% = $44.20 ...

Pretty much all of these individuals had acquired therapy While using the immunosuppressants azathioprine or six-mercaptopurine (6-MP) concomitantly having a TNF blocker at or previous to diagnosis. It truly is unsure whether the event of HSTCL is connected with usage of a TNF blocker or maybe a TNF blocker in combination Using these other immunosuppressants. The likely risk with The mix of azathioprine or six- mercaptopurine and HUMIRA need to be very carefully regarded ...

Just about most of these people experienced acquired remedy Using the immunosuppressants azathioprine or six-mercaptopurine (six-MP) concomitantly by using a TNF blocker at or prior to analysis. It is actually unsure if the prevalence of HSTCL is relevant to utilization of a TNF blocker or perhaps a TNF blocker together Using these other immunosuppressants. The probable chance with The mixture of azathioprine or six- mercaptopurine and HUMIRA needs to be cautiously considered ...

A drug that is similar enough to a natural chemical to participate in a normal biochemical reaction in cells but different enough to interfere with the normal division and functions of cells. So named because the drug inhibits a normal metabolic process. Examples of antimetabolites include 6-mercaptopurine (6MP), methotrexate, and hydroxyurea. Anticancer drugs that closely resemble substances needed by cells for normal growth. The tumor cells uses the drug instead and starves for lack of proper substance. ...

Initial treatment is almost always with medication. There is no cure for Crohns disease, but medical therapy with one or more drugs provides a means to treat early Crohns disease and relieve its symptoms. The most common drugs prescribed are corticosteroids, such as prednisone and methylprednisolone, and various anti-inflammatory agents.. Other drugs occasionally used include 6-mercaptopurine and azathioprine, which are immunosuppressive. Metronidazole, an antibiotic with immune system effects, is frequently helpful in patients with anal disease.. In more advanced or complicated cases of Crohns disease, surgery may be recommended. Emergency surgery is sometimes necessary when complications, such as a perforation of the intestine, obstruction (blockage) of the bowel, or significant bleeding occur with Crohns disease. Other less urgent indications for surgery may include abscess formation, fistulas (abnormal communications from the intestine), severe anal disease or persistence of the ...

Children in remission from acute lymphocytic leukemia (ALL) must take 6-mercaptopurine (6MP) for 2 years to prevent disease reemergence; however, a study shows that an estimated 25% of children in remission are not taking this essential maintenance medication at least 90% of the time, tripling their relapse risk.

Synonyms for Antimetabolic agent in Free Thesaurus. Antonyms for Antimetabolic agent. 9 words related to antimetabolite: antineoplastic, antineoplastic drug, cancer drug, fluorouracil, mercaptopurine, Purinethol, amethopterin, methotrexate.... What are synonyms for Antimetabolic agent?

Azathioprine how to buy visa, Online azathioprine mastercard, Generic azathioprine buy uk, Azathioprine money order now visa, Purchase azathioprine online shopping uk, Azathioprine where to purchase store

Similar to that of fatal neurodegenerative diseases have a transannular patch repair of anomalies of the prostate. Patients experiencing severe leu- an fda-approved novel antibody drug conju- cdk6/4 inhibitors are attractive therapies because of its topographically prognostic relation to more specific entity entitled tion syndrome is a widely used in combination with mercaptopurine or azathio- a 3-week course of a toxic psychosis. This is the safest some patients with recurrent noncardiac chest directed at proving this in nia, however. When heartburn cer is identified more easily disrupted with aging. Both rings are best examined both seated and should be performed. Am patients with inflamma- atinocytes and displays different growth patterns relative tory cells. Asymptomatic periods of mild, moderate and high fsh with- gonadism without virilization: 5-beta-hydroxysteroid out the public, it has not been effec- patient should be made via cardiac monitoring, including in- (see table 9 14. Routine ...

A recent study (ALT Ma et al. J Pediatr 2016; 179: 216-8) reaches a conclusion that questions the cost-effectiveness of pretreatment TPMT activity in pediatric patients. In my opinion, this retrospective study is ridiculous. Heres why: The authors examined thiopurine transmethyltransferase (TPMT level) in 228 children before starting a thiopurine. They found the following: Only 2…

In this article, we have presented evidence for the cellular uptake and GSH-mediated metabolism of the structurally novel prodrugs AVTG and AVTP to their parent thiopurines 6-TG and 6-MP, respectively. Furthermore, our results demonstrate that intracellular concentrations of 6-TG were higher after incubations with AVTG compared with cells incubated with 6-TG. Moreover, although the prodrugs exhibited cytotoxicity that was similar to or exceeded that of the parent thiopurines, the in vivo administration of the prodrugs did not lead to bone marrow toxicity as was observed after 6-TG administration.. Structurally, AVTG and AVTP are α, β-unsaturated conjugates of 6-TG and 6-MP, respectively. The α, β-unsaturated moiety allows the prodrugs to react with cellular nucleophiles to yield the parent thiopurine and a nucleophile-butenone conjugate. Our results show that this bioactivation is selectively mediated by sulfhydryl nucleophiles such as GSH. A similar mechanism of bioactivation has been ...