Intensity-Modulated Radiotherapy With a Simultaneous Integrated Boost in Rectal Cancer.

AIMS: Dose-response curves suggest that higher doses of radiotherapy improve the complete response rate in rectal cancer. The UK adopted the EXPERT trial dose and fractionation, 45 Gy in 25 fractions to the pelvis with a sequential 9 Gy in five fractions to the gross tumour, in patients where the aim was to maximise the complete response. In the Oxford University Hospital NHS Foundation Trust (Oxford, UK) we deliver a biological equivalent dose (BED5) in selected patients using intensity-modulated radiotherapy (IMRT) with a simultaneous integrated boost (SIB) in 25 fractions. We carried out a retrospective analysis of our series to: (i) document the toxicity of this protocol; (ii) ascertain whether dose constraints from RTOG 0822 were appropriate; (iii) assess the response. MATERIALS AND METHODS: The demographics and treatment details for all consecutive patients treated with this protocol were collected using electronic systems. Patients received 45 Gy to the elective nodes and 52 Gy using a SIB to the gross tumour with capecitabine chemotherapy using IMRT or RapidArc plans. Acute toxicity was collected prospectively during weekly reviews. For the purpose of this study, a dedicated gastrointestinal radiologist reviewed all baseline and post-treatment magnetic resonance images and assigned a magnetic resonance tumour regression grade (mrTRG). RESULTS: Seventy-one patients were identified. Seventy completed radiotherapy with a median overall treatment time of 34 days (range 32-36 days); 67.6% received full-dose chemotherapy, with 21.2% receiving a reduced dose. There was a 4.2% incidence of grade 3+ non-haematological toxicity and 1.5% grade 3 + haematological toxicity. 4.2% were admitted during their radiotherapy, with one death due to a pelvic abscess. The RTOG 0822 constraints were achieved in ≥75% of cases, other than the high-dose bladder constraint. mrTRG 1-2 was seen in 47.8%, with mrTRG 1 seen in 23.9%. CONCLUSIONS: We suggest that our protocol shows acceptable acute toxicity, with promising mrTRG results, and could be adopted by centres as an IMRT equivalent dose for EXPERT dose and fractionation.

Morphometry of the nulliparous pelvic floor.

OBJECTIVES: To describe morphometry of the pelvic floor in a large population of nulliparous women, comparing those with and those without pelvic pain. We also aimed to assess its association with characteristics such as age and body mass index (BMI). METHODS: This was a prospective study performed between January 2013 and November 2015 in non-pregnant nulliparous women attending a general gynecology clinic. Following collection of demographic data, women were examined using translabial four-dimensional (4D) ultrasound. Dynamic volumes of pelvic floor muscle were obtained at rest, on maximal contraction and on Valsalva maneuver, and analyzed at a later date by an assessor blinded to demographic details. Standard measurements for each volume included levator hiatal area and anteroposterior and transverse diameters, and pubovisceral muscle length and width. Subanalysis was performed comparing women with and those without pelvic pain. Linear regression analysis was performed to assess the association between characteristics, including age and BMI, and levator hiatal area at rest. RESULTS: Three hundred and sixty eight nulliparous women were examined using translabial 4D ultrasound. Median levator hiatal area was 10.62 cm2 at rest, 11.95 cm2 on Valsalva maneuver and 8.18 cm2 on maximal contraction. There was no difference between women with and those without pelvic pain when comparing biometric measurements of the pelvic floor musculature, except for in pubovisceral muscle width during the contraction phase. Regression analysis demonstrated that higher age and BMI were associated with increased levator hiatal area measurement. CONCLUSIONS: Pelvic floor morphometry in nulliparous women is unchanged by pelvic pain, but levator hiatal area is increased in women with higher BMI and age. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Four-dimensional ultrasound guidance for pelvic floor Botulinum toxin-A injection in chronic pelvic pain: a novel technique.

OBJECTIVE: Botulinum toxin-A (BoNT-A) is used in the treatment of pelvic floor muscle overactivity associated with chronic pelvic pain (CPP) when conservative methods such as physiotherapy are not effective or appropriate. Traditional injection techniques require finger-guided palpation of pelvic floor muscles with concurrent insertion of the needle. The aim of this study was to describe a novel technique for the injection of BoNT-A into the pelvic floor musculature using four-dimensional ultrasound (4D-US) guidance. METHODS: Thirty-one BoNT-A injections were performed using the new technique between October 2013 and January 2016, on women scheduled to have BoNT-A injection for pelvic floor muscle overactivity and CPP. The pelvic floor was assessed by 4D-US. A test injection of saline was performed to confirm location of the needle, then BoNT-A was injected into the muscle under ultrasound guidance, using 4D-US to confirm that the fluid expanded and tracked along muscle fibers. RESULTS: The saline test confirmed correct location of the needle following a median of 1 (range, 1-3) attempt at needle placement. In all 31 instances, satisfactory injection of BoNT-A, with 4D-US confirmation of fluid expansion within the muscle body, was performed. CONCLUSIONS: Injection of BoNT-A under 4D-US guidance is feasible and allows accurate placement into the target muscle in women with pelvic floor muscle overactivity associated with CPP. This technique may provide a safer alternative to finger-guided methods, owing to a lower likelihood of operator needle-stick injury. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Endometriosis fertility index predicts live births following surgical resection of moderate and severe endometriosis.

STUDY QUESTION: Can live birth be accurately predicted following surgical resection of moderate-severe (Stage III-IV) endometriosis? SUMMARY ANSWER: Live births can accurately be predicted with the endometriosis fertility index (EFI), with adnexal function being the most important factor to predict non-assisted reproductive technology (non-ART) fertility or the requirement for ART (www.endometriosisefi.com). WHAT IS KNOWN ALREADY: Fertility prognosis is important to many women with severe endometriosis. Controversy persists regarding optimal post-operative management to achieve pregnancy and the counselling of patients regarding duration of conventional treatments before undergoing ART. The EFI is reported to correlate with expectant management pregnancy rate, although external validation has been performed without specifically addressing fertility in women with moderate and severe endometriosis. STUDY DESIGN, SIZE, DURATION: Retrospective cohort study of 279 women from September 2001 to June 2016. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: We included women undergoing laparoscopic resection of Stage III-IV endometriosis who attempted pregnancy post-operatively. The EFI was calculated based on detailed operative reports and surgical images. Fertility outcomes were obtained by direct patient contact. Kaplan-Meier model, log rank test and Cox regression were used for analyses. MAIN RESULTS AND THE ROLE OF CHANCE: The follow-up rate was 84% with a mean duration of 4.1 years. A total of 147 women (63%) had a live birth following surgery, 94 of them (64%) without ART. The EFI was highly associated with live births (P < 0.001): for women with an EFI of 0-2 the estimated cumulative non-ART live birth rate at five years was 0% and steadily increased up to 91% with an EFI of 9-10, while the proportion of women who attempted ART and had a live birth, steadily increased from 38 to 71% among the same EFI strata (P = 0.1). A low least function score was the most significant predictor of failure (P = 0.003), followed by having had a previous resection (P = 0.019) or incomplete resection (P = 0.028), being older than 40 compared to <35 years of age (P = 0.027), and having leiomyomas (P = 0.037). LIMITATIONS REASONS FOR CAUTION: The main limitation of this study is its retrospective design. Imprecision was higher with low EFI due to smaller sample size in this subgroup. Finally, the EFI is somewhat subjective and could be prone to intra- and inter-observer variations. WIDER IMPLICATIONS OF THE FINDINGS: Women with a high EFI score have excellent fertility prognosis and may be advised to try to become pregnant with timed intercourse compared to women with a low score, for which prompt referral to ART seems more reasonable. Other prognostic factors can be used to guide the management of women with an intermediate EFI score. These data follow women over many years post-resection and represent longitudinal fertility data rarely demonstrated in such a cohort. The location and impact of lesions on the ability of the adnexa to function seems crucial for the fertility prognosis and should be further investigated. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the GRACE Research funds. S.M.-L. is the recipient of a Training Award from the Fonds de Recherche Quebec-Sante. D.A. is the primary author of the Endometriosis Fertility Index. All authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Probable glucometer interference caused by topical iodine solution test site preparation.

WHAT IS KNOWN AND OBJECTIVE: Use of disinfectants, such as alcohol prep pads, for test site preparation have demonstrated alterations in glucose readings. One case report details an overestimation of blood glucose (BG) readings when using Chemstrip bG and Visidex reagent test strips after cleaning test site with povidone-iodine swabs CASE SUMMARY: We present a case of a clinically relevant probable drug-device interaction between topical iodine and a point-of-care glucometer in a 28 year old pregnant woman of Chinese descent. In this case, the use of 10% povidone-iodine solution on the testing site before lancing likely resulted in variable and inaccurate BG readings, which was not reproduced when the patient used hand washing instead of iodine. WHAT IS NEW AND CONCLUSION: Our report expands on this prior knowledge by demonstrating that such an alteration associated with iodine can occur with modern electrochemical glucometers. In patients that have aberrant or variable BG readings, providers should investigate for improper testing technique.

A single test to assay warfarin, dabigatran, rivaroxaban, apixaban, unfractionated heparin, and enoxaparin in plasma.

UNLABELLED: Essentials Simple and fast assaying of different anticoagulants (ACs) is useful in emergent situations. We used highly diluted prothrombin time (dPT) or highly diluted Fiix-PT (dFiix-PT) to assay ACs. Both tests could quantify target specific anticoagulants and warfarin anticoagulation. Improved results were consistently observed with the dFiix-PT compared with the dPT. SUMMARY: Background Assaying anticoagulants is useful in emergency situations or before surgery. Different specific assays are currently needed depending on the anticoagulant. Objectives We hypothesized that levels of warfarin, dabigatran, rivaroxaban, apixaban, and heparins could be measured with use of the diluted prothrombin time (dPT) and diluted Fiix-PT (dFiix-PT), using highly diluted thromboplastin (TP). The latter test is affected only by reduced levels of active factors II and X but corrects test plasma for other deficiencies Methods Increasing TP dilutions were used to identify suitable dilutions to measure dabigatran, rivaroxaban, apixaban, unfractionated heparin (UFH), and enoxaparin. Calibrators containing known amounts of direct oral anticoagulants (DOACs) were used to make standard curves. Citrated plasma samples were obtained from patients taking warfarin or DOACs with known drug concentrations as determined by specific assays. Results The dFiix-PT at a TP dilution of 1:1156 could be used to measure all of the drugs tested at therapeutic concentrations except for fondaparinux. The dPT achieved the same but required two TP dilutions (1:750 and 1:300). The warfarin effect could be assessed by using dFiix-PT at 1:1156 with a PT ratio identical to the international normalized ratio. Six different TPs yielded similar results, but two were less sensitive. Dabigatran, rivaroxaban, and apixaban could be accurately measured in patient samples using both dilute PT assays, but a better correlation was consistently observed between the dFiix-PT and specific assays than with the dPT. Conclusion The dFiix-PT using a single dilution of TP may be suitable to assess the anticoagulant effects of warfarin, dabigatran, rivaroxaban, apixaban, heparin, and enoxaparin.

Evaluation of prescribing and patient use of target-specific oral anticoagulants in the outpatient setting.

WHAT IS KNOWN AND OBJECTIVE: Pharmacist-managed anticoagulation programmes have been shown to improve appropriate use of warfarin, but few programmes have included the new target-specific oral anticoagulants (TSOACs) in their protocols. A greater understanding of TSOAC prescribing, monitoring and administration is needed to identify common errors in the current outpatient practice. The objective of this study is to assess the rate of errors related to prescribing, baseline monitoring and patient administration of TSOACs. METHODS: A retrospective chart review was conducted to identify patients on TSOAC therapy in each of four outpatient practice sites. Data were abstracted to include TSOAC indication, dosage and frequency prescribed, pertinent past medical history, and laboratory monitoring obtained at the time of TSOAC initiation. In addition, patients were contacted by telephone to assess TSOAC adherence, storage, administration and incidence of adverse events. RESULTS AND DISCUSSION: A total of 395 patients were included in the evaluation. Prescribers did not obtain baseline laboratory values within 1 week before or after the time of TSOAC initiation for a majority of study patients. At the time of TSOAC initiation, two patients had abnormally elevated alanine aminotransferase, six had elevated total bilirubin, and 43 had low haemoglobin. A majority (61%) of study patients were prescribed an appropriate TSOAC dose based upon their indication and renal function; however, dosing accuracy could not be determined for all patients as baseline serum creatinine was not obtained by prescribers for 148 patients (37%) at the time of prescribing. TSOACs were dosed inappropriately according to baseline serum creatinine in six patients, and two patients receiving treatment for venous thromboembolism were maintained on a high dose of rivaroxaban for an inappropriate duration. A total of 157 (40%) patients were available by phone and agreed to answer questions regarding their current TSOAC use. Twenty-four patients (23%) reported taking rivaroxaban inappropriately without food, and six patients (14%) endorsed inappropriate storage of dabigatran. Ten patients (6%) reported missing at least one TSOAC dose per week, and 25 (16%) described minor bleeding with their TSOAC. WHAT IS NEW AND CONCLUSION: Inappropriate prescribing, monitoring and administration of TSOACs occurred frequently in patients not formally enrolled in an anticoagulation monitoring programme. These results indicate a need for more thorough patient education at the time of TSOAC initiation, as well as improved prescriber education regarding recommended TSOAC dosing and monitoring.

Evaluating the use of commercial drug-specific calibrators for determining PT and APTT reagent sensitivity to dabigatran and rivaroxaban.

Suitable laboratory methodologies for quantifying the non-vitamin K oral anticoagulants (NOAC) include liquid chromatography-tandem mass spectrometry (LC-MS/MS) or drug-calibrated assays such as the dilute thrombin time for dabigatran or anti-Xa measurements for rivaroxaban. In situations when these tests are unavailable, it has been suggested that using commercial drug calibrators on APTT and PT assays would theoretically provide reagent sensitivity to these drugs. The purpose of this study was to determine whether commercial drug calibrators deliver similar reagent sensitivity information as samples from patients receiving dabigatran or rivaroxaban as part of their routine care. Two laboratory sites tested commercial calibrator material for dabigatran and rivaroxaban (Hyphen Biomedical) using PT and APTT reagents and data was compared to samples collected from patients taking NOACs that were quantified by LC-MS/MS. Correlation statistics and calculating the amount of drug required to double the clotting time of normal plasma were performed. All drug calibrator material correlated more strongly (R²> 0.95) for any reagent/drug combination than patient samples (R² ranged from 0.29-0.86). Dabigatran calibrator results and patient data were equivalent for SynthASil and PTT-A APTT reagents. The dabigatran and rivaroxaban calibrator material over-estimated drug sensitivity for all PT reagents when compared to sensitivity data calculated based on drug levels obtained by LC-MS/MS from patient samples. In conclusion, drug-specific calibrators overestimated reagent sensitivity which may underestimate in vivo drug concentration in a given patient. Further studies are required to assess whether this method of determining relative sensitivity of NOAC on routine coagulation assays should be recommended.

Performance of coagulation tests in patients on therapeutic doses of dabigatran: a cross-sectional pharmacodynamic study based on peak and trough plasma levels.

BACKGROUND: Knowledge of anticoagulation status during dabigatran therapy may be desirable in certain clinical situations. OBJECTIVE: To determine the coagulation tests that are most useful for assessing dabigatran's anticoagulant effect. METHODS: Peak and trough blood samples from 35 patients taking dabigatran 150 mg twice daily, and one sample each from 30 non-anticoagulated individuals, were collected. Mass spectrometry and various coagulation assays were performed. 'Therapeutic range' was defined as the range of plasma dabigatran concentrations determined by mass spectrometry between the 2.5th and 97.5th percentiles of all values. RESULTS: The therapeutic range was 27-411 ng mL(-1) . The prothrombin time (PT) and activated partial thromboplastin time (APTT), determined with multiple reagents, and activated clotting time (ACT) were insensitive to therapeutic dabigatran: 29%, 18% and 40% of samples had a normal PT, APTT, and ACT, respectively. However, normal PT, ACT and APTT ruled out dabigatran levels above the 75th percentile. The thrombin clotting time (TCT) correlated well and linearly with dabigatran levels below the 50th percentile, but was unmeasurable above it. The dilute thrombin time, ecarin clotting time and ecarin chromogenic assay showed linear correlations with dabigatran levels over a broad range, and identified therapeutic and supratherapeutic levels. CONCLUSIONS: The prothrombin time, APTT and ACT are often normal in spite of therapeutic dabigatran plasma levels. The TCT is useful for detecting minimal dabigatran levels. The dilute thrombin time and chromogenic and clotting ecarin assays accurately identify therapeutic and supratherapeutic dabigatran levels. This trial is registered at www.clinicaltrials.gov (#NCT01588327).

Improvement in pelvic pain with botulinum toxin type A - Single vs. repeat injections.

The aim of this prospective study was to report the outcomes of pain and vaginal pressures of successive botulinum toxin type A injections for women with objective pelvic floor muscle overactivity and a two-year history of pelvic pain. Between 2005 and 2008, 37 women underwent injection of 100 IU of botulinum toxin type A into the puborectalis and pubococcygeous muscles with dysmenorrhoea, dyspareunia, dyschesia, and non-menstrual pelvic pain assessed using a visual analogue scale (VAS), and vaginal pressure measured by vaginal manometry, at 0, 4, 12 and 26 weeks from each injection. 26 women (70%) had one injection of botulinum toxin type A and 11 (30%) had 2 or more injections. The second injection was performed at the earliest at 26 weeks after the first, with subsequent injections having a median time to re-injection of 33.4 weeks (range 9.4-122.7 weeks). Single and repeated injections both demonstrated a statistically significant reduction in dyspareunia by VAS scores from 54 to 30 in the single injection group and from 51 to 23 in the multiple injection group (p = .001), non-menstrual pelvic pain VAS from 37 to 25 (p = .04), as well as vaginal pressures; 40 versus 34 cm H(2)O (p = .02). No statistically significant difference in dysmenorrhoea or dyschesia was observed for either group from their baseline scores. Multiple injections of botulinum toxin type A in women with pelvic floor muscle overactivity provide significant relief from dyspareunia and non-menstrual pelvic pain. The upper limit between re-injection is not yet determined, nor is the maximum number of treatments. Clinical outcomes for single and subsequent injection of botulinum toxin type A for recurrent pelvic pain are equivalent. Women who have had benefit from a single injection of botulinum toxin type A can be reassured that if symptoms reoccur, repeated injections can be expected to be equally efficacious.

Diagnosis and management of endometrial polyps: a critical review of the literature.

This review article summarizes the salient literature on the diagnosis and management of endometrial polyps. Electronic resources including Medline, PubMed, CINAHL, The Cochrane Library (including the Cochrane Database of Systematic Reviews), Current Contents, and EMBASE were searched with the MeSH terms including all subheadings and keywords endometrial polyps, abnormal uterine bleeding, polypectomy, polyp management, polyp and diagnosis, and polyp and malignancy. There is a paucity of level I evidence in the literature on the diagnosis and management of this common gynecologic disease. Noninvasive investigations such as transvaginal ultrasonography, with or without the use of 3-dimensional ultrasonography and contrast techniques remain the mainstay of first-line investigation. Hysteroscopic resection is the most effective management for endometrial polyps and allows histologic assessment, whereas blind biopsy or curettage has low diagnostic accuracy and should not be performed. This article will review the cause, epidemiology, clinical presentation, diagnostic investigations, and management of endometrial polyps.

Spatially selective melting and evaporation of nanosized gold particles.

We have developed an atomic force microscope-tip-based concept to pattern metallic nanoparticles on substrates. This new process has the potential to control the assembly of nanometer sized particles by combining their unique optical and thermophysical properties and is a flexible and low energy method of patterning at the nanoscale. The proof of concept is detailed by preliminary experimental work showing selective melting and evaporation of groups of 50 and 100 nm gold spherical particles.

Formation of the quaternary ammonium-linked glucuronide of nicotine in human liver microsomes: identification and stereoselectivity in the kinetics.

The formation of the N1-glucuronide metabolite of each nicotine enantiomer was studied in pooled human liver microsomes (n = 6). The metabolite formed from natural S(-)-nicotine was identified by comparison of the high-pressure liquid chromatography (HPLC) retention time and positive ion electrospray ionization-mass spectral characteristics with a synthetic reference standard. A radiometric HPLC method was used to quantify the metabolite. The specificity of the assay method was demonstrated by experiments in which beta-glucuronidase treatment of incubated assay samples resulted in elimination of the peak due to the N1-glucuronide metabolite. The glucuronides of S(-)- and R(+)-nicotine were formed by one-enzyme kinetics, with K(m) values of 0.11 and 0.23 mM and V(max) values of 132 and 70 pmol/min/mg of protein, respectively. There is marked stereoselectivity in the apparent intrinsic clearance values (V(max)/K(m)) in that the value for S(-)-nicotine is 4 times greater than for the R(+)-isomer (1.2 versus 0.31 microl/min/mg of protein).

Quaternary ammonium-linked glucuronidation of 1-substituted imidazoles: studies of human UDP-glucuronosyltransferases involved and substrate specificities.

A series of eight 1-substituted imidazoles was investigated as model substrates for glucuronidation at an aromatic tertiary amine of polyaza heterocyclic ring systems. The human UDP-glucuronosyltransferases (UGTs) involved and substrate specificities were investigated. Nine expressed enzymes (UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A7, UGT1A9, UGT1A10, UGT2B7, and UGT2B15) were examined, but only UGT1A4 catalyzed the formation of a quaternary ammonium-linked glucuronide metabolite for six of the substrates. UGT1A3 also catalyzed the glucuronidation of the previously investigated 1-phenylimidazole but none of the newly investigated compounds. No glucuronidation was observed with 1-(4-nitrophenyl)imidazole, the compound with the 4-phenyl substituent with the largest electron withdrawing effect. The incubation conditions for the determination of the kinetic constants for UGT1A4 catalysis of six substrates were optimized and included incubation at pH 7.4 with alamethicin at 10 microg/mg of protein. Latency disrupting agents, including alamethicin and sonication, enhanced glucuronidation 1.25-fold at most. There were 17.5- and 2.2-fold variations in the apparent K(m) (range, 0.18-3.15 mM) and V(max) values (range, 0.16-0.35 nmol/min/mg of protein). Linear correlation analyses between UGT1A4 kinetics and substrate physicochemical parameters showed significant correlation between V(max) and both the partition coefficient (log P, n-octanol/water) and pK(a) and between K(m) and pK(a), thereby indicating that the lipophilicity and the ease of availability of the tertiary amine lone pair of electrons of the substrate are important with respect to enzyme catalysis.

Characterization of rat liver microsomal metabolites of clivorine, an hepatotoxic otonecine-type pyrrolizidine alkaloid.

The metabolism of the hepatotoxic otonecine-type pyrrolizidine alkaloid (PA), clivorine, was investigated using rat liver microsomes. The metabolites dehydroretronecine (DHR), 7-glutathionyldehydroretronecine (7-GSH-DHR), 7, 9-diglutathionyldehydroretronecine (7,9-diGSH-DHR), and clivoric acid were identified using chromatographic and mass spectrometric analyses. NMR characterizations were also performed on the isolated clivoric acid and the synthetic 7-GSH-DHR and 7,9-diGSH-DHR. The results indicated that the two glutathione (GSH) conjugates were formed by reaction of the unstable toxic pyrrolic ester with GSH added in the microsomal incubation system, whereas DHR was generated from hydrolysis of the unstable pyrrolic ester, and that clivoric acid was produced from all these further conversions of the unstable pyrrolic ester. Furthermore, tissue-bound pyrroles were also determined to be present after microsomal incubation of clivorine. Clivoric acid has not been previously identified, and DHR and 7, 9-diGSH-DHR were found, for the first time, as metabolites of an otonecine-type PA, while 7-GSH-DHR was previously reported by us to be a microsomal metabolite of clivorine. The in vitro metabolic pathway of clivorine was delineated to be the initial formation of the unstable pyrrolic ester, which then may undergo hydrolysis, GSH conjugations, or covalent binding with hepatic tissues that may lead to hepatotoxicity. The present definitive identification of four pyrrolic ester-related metabolites of clivorine and indirect determination of bound pyrroles provide the strongest evidence to date to support the hypothesis that the formation of an unstable pyrrolic ester plays a key role in otonecine-type PA-induced hepatotoxicity.

Synthesis and identification of the quaternary ammonium-linked glucuronide of 1-phenylimidazole in human liver microsomes and investigation of the human UDP-glucuronosyltransferases involved.

1-Phenylimidazole was investigated as a potential model substrate with respect to formation of a quaternary ammonium-linked glucuronide (N(+)-glucuronide) at an aromatic type tertiary amine. A reference sample of the potential N(+)-glucuronide metabolite of 1-phenylimidazole was obtained by organic synthesis. The structural identity of the metabolite formed by incubation of 1-phenylimidazole with human liver microsomes was proven to be the N(+)-glucuronide by exhibiting the same HPLC retention time and electrospray ionization mass spectrum as the reference sample. The screening of 1-phenylimidazole against a panel of nine expressed human UDP-glucuronosyltransferases indicated the involvement of UGT1A3 and UGT1A4 in the formation of the N(+)-glucuronide metabolite.

Characterization of two structural forms of otonecine-type pyrrolizidine alkaloids from Ligularia hodgsonii by NMR spectroscopy.

Clivorine (1) and ligularine (2), two hepatotoxic otonecine-type pyrrolizidine alkaloids isolated from Ligularia hodgsonii, an antitussive traditional Chinese medicine, were investigated in CDCl(3) and D(2)O by various NMR techniques to delineate why this type of alkaloid displays uncharacteristic solubility properties by dissolving in both nonpolar organic and aqueous solutions. The results demonstrated that both alkaloids exist in a non-ionized form in CDCl(3), but in an ionized form in D(2)O, suggesting that this unique dual solubility may play a role in the intoxication resultant from consumption of water extracts of herbs, including herbal teas, containing otonecine-type pyrrolizidine alkaloids.