Dimethylarginines correlate to common carotid artery wall layer dimensions and cardiovascular risk factors in pregnant women with/without preeclampsia: A group comparative study.

OBJECTIVES: Asymmetric- and symmetric dimethylarginines (ADMA, SDMA) are elevated in cardiovascular disease (CVD). Preeclampsia is a pregnancy-specific syndrome and is an independent risk factor for subsequent CVD. Aims were to investigate whether ADMA, SDMA levels and l-arginine/ADMA and l-arginine/SDMA ratios during pregnancy and their changes from pregnancy to postpartum are associated to arterial wall layer dimensions and cardiovascular risk factors in women with and without preeclampsia. STUDY DESIGN: Dimethylarginines were analyzed by LC-MS, and the common-carotid-artery (CCA) intima and media thicknesses were estimated using 22-MHz non-invasive ultrasonography in women with preeclampsia (cases = 48) and normal pregnancies (controls = 58) in similar gestational age, with reassessment one-year postpartum. A thick intima, thin media and high intima/media ratio (I/M) indicates a less healthy arterial wall. RESULTS: The median age of cases and controls was 30 years. During pregnancy, women with preeclampsia had higher plasma ADMA, SDMA and lower l-arginine/ADMA and l-arginine/SDMA (all p < 0.01) than women with normal pregnancies. Further, ADMA, SDMA, l-arginine/ADMA and l-arginine/SDMA correlated to intima thickness (rs = 0.33/0.33/-0.33/-0.35 and p < 0.01), I/M (rs = 0.26/0.28/-0.22/-0.26 and p < 0.05) and mean arterial pressure (MAP) (rs = 0.43/0.42/-0.39/-0.40 and p < 0.0001). Changes in ADMA, SDMA and l-arginine/SDMA from pregnancy to postpartum correlated to changes in intima thickness (rs = 0.22/0.32/-0.21 and p < 0.05/<0.01/<0.05), I/M (rs = 0.22/0.31/0.08 and p < 0.05/<0.01/=0.43) and MAP (rs = 0.31/0.53/-0.25 and p < 0.01/<0.001/<0.05). No correlations were found for conventional CCA intima-media-thickness. CONCLUSIONS: Dimethylarginines were associated to signs of adverse effects on arterial wall layer dimensions and cardiovascular risk factors in women with and without preeclampsia, during pregnancy and to their changes from pregnancy up to one-year postpartum.

Sub-clinical atherosclerosis in the common carotid artery in women with/without previous pre-eclampsia: A seven-year follow-up.

BACKGROUND AND AIMS: Pre-eclampsia is associated with increased risk of cardiovascular disease and premature death. However, conventional common carotid artery intima-media thickness (CCA-IMT) measurement does not reflect this. In contrast, measurement of the individual CCA intima and media thicknesses clearly indicates increased vascular risk both at diagnosis and about one year after pre-eclampsia. This study examined whether individual CCA wall layers, risk factors for cardiovascular disease, and markers of endothelial dysfunction had normalized or remained unfavorable seven years after pre-eclampsia. METHODS: The individual CCA intima and media thicknesses were measured using 22 MHz ultrasound. Conventional cardiovascular risk factors were recorded. A thick intima, thin media and high intima/media thickness ratio (I/M) are signs of sub-clinical atherosclerosis. RESULTS: The median age of women with previous pre-eclampsia (cases = 23) or normal pregnancies (controls = 35) was 39/37 years. At follow-up (median about seven years), the intima remained thicker and the I/M was higher in cases than in controls [all p < 0.0001; p < 0.001 after adjustment for time to follow-up, body mass index (BMI), and mean arterial pressure (MAP)], whereas the CCA-IMT was illogically thinner. Further, BMI, MAP, hip circumference, abdominal height, serum endostatin and apolipoprotein B levels were higher in cases (all p < 0.05). Intima and I/M measurements were correlated with age, MAP, endostatin and apolipoprotein B, whereas no logical correlations were found for CCA-IMT. CONCLUSIONS: The arteries in cases but not controls were still adversely affected after seven years. Measuring intima thickness and I/M appears preferable to measuring CCA-IMT for demonstrating vascular risk after pre-eclampsia.

Obstructive sleep apnea during rapid eye movement sleep is associated with early signs of atherosclerosis in women.

Study Objectives: Although obstructive sleep apnea (OSA) is associated with overall cardiovascular disease and mortality, the association with atherosclerotic cardiovascular disease is less clear, especially in women. Recently, it has been suggested that OSA during rapid eye movement (REM) sleep, associated with long apneas and deep desaturations, could have severe cardiometabolic consequences. The aim of this study was to investigate whether OSA during REM sleep is associated with early signs of atherosclerosis in a population-based sample of women. Methods: In the community-based "Sleep and Health in Women" (SHE) cohort study, 400 women underwent polysomnography, anthropometric measurements, blood sampling, blood pressure measurement, and answered questionnaires. Ten years later, 201 of the original participants, free of known atherosclerotic disease at baseline and without continuous positive airway pressure treatment for OSA, underwent a high-frequency ultrasound of the common carotid artery to assess the individual thickness of the layers of the artery wall. Results: Severe OSA during REM sleep (REM apnea-hypopnea index [AHI] ≥ 30) was associated with a thicker intima. This association was still significant after adjustment for age, body mass index, alcohol, and smoking, as well as for further adjustment for systolic blood pressure, low-density lipoprotein, C-reactive protein, and diabetes (ß-coefficient, 0.008; p-value, 0.022). The association between a REM AHI of ≥30 and intima thickness was also seen in women with no or mild OSA and normal non-REM AHI. Conclusions: In this study of a community-based sample of women, severe OSA during REM sleep was independently associated with early signs of atherosclerosis.

Serum Pentraxin 3 is associated with signs of arterial alteration in women with preeclampsia.

BACKGROUND: Preeclampsia (PE) in pregnancy is a state of exaggerated inflammation and is associated with an increased risk of cardiovascular disease (CVD) later in life. Levels of pentraxin 3 (PTX3), a novel inflammation marker, are increased during PE and in individuals with CVD. The primary aim of this study was to assess whether serum PTX3 in women with PE is associated with adverse arterial effects; a thicker intima and higher intima/media (I/M) ratio in the common carotid artery (CCA). METHODS: Serum PTX3 levels were measured using commercially available enzyme-linked immunosorbent assay kits, and individual CCA intima and media thicknesses were estimated by 22MHz non-invasive ultrasound in 55 women at PE diagnosis and 64 women with normal pregnancies at a similar gestational age, and about one year postpartum. A thick intima, thin media and high I/M ratio indicate a less healthy artery wall. RESULTS: During pregnancy serum PTX3 correlated positively with intima thickness and I/M ratio but negatively with media thickness (all p<0.0001), indicating adverse arterial effects. About one year postpartum, PTX3 levels had decreased in both groups and there remained no significant group difference or significant correlation with CCA wall layers. CONCLUSIONS: Higher levels of serum PTX3 in women with PE were significantly associated with signs of adverse arterial effects during pregnancy, but not one year postpartum, supporting the rapid dynamics of PTX3.

Cerebral Biomarkers in Women With Preeclampsia Are Still Elevated 1 Year Postpartum.

BACKGROUND: There is evidence of cerebral involvement among women with preeclampsia. Levels of the cerebral biomarkers neuron-specific enolase (NSE) and S100B are elevated during pregnancy in women developing preeclampsia. It is although not known if these biomarkers return to normal range postpartum. The aim with this study was to compare levels of S100B and NSE during pregnancy and 1 year postpartum in women who have had preeclampsia to women with normal pregnancies. METHODS: This study was a longitudinal study of cases (n = 53) with preeclampsia and controls (n = 58) consisted of normal pregnant women in matched gestational weeks. Plasma samples were collected at inclusion during pregnancy and 1 year postpartum. Plasma samples were analyzed for levels of S100B and NSE by enzyme-linked immunosorbent assays kits. RESULTS: Levels of NSE and S100B in women with preeclampsia were higher during pregnancy than in women with normal pregnancies. One year postpartum, women who have had preeclampsia still had a higher median level of both NSE (5.07 vs. 4.28 µg/l, P < 0.05) and S100B (0.07 vs. 0.06 µg/l, P < 0.05) compared to women with previous normal pregnancies. High levels of NSE and S100B postpartum remained associated with previous preeclampsia after adjustment for confounding factors. Levels of NSE correlated to S100B during pregnancy and postpartum. CONCLUSIONS: Levels of NSE and S100B are still elevated 1 year postpartum in women who have had preeclampsia in contrast to women with previous normal pregnancies. We hypothesize that there might be a persistent cerebral involvement among women with preeclampsia even 1 year postpartum.

Individual common carotid artery wall layer dimensions, but not carotid intima-media thickness, indicate increased cardiovascular risk in women with preeclampsia: an investigation using noninvasive high-frequency ultrasound.

BACKGROUND: Preeclampsia (PE) is associated with increased risk of cardiovascular disease later in life. Ultrasound assessment of the common carotid artery intima-media thickness (IMT) during or after PE has not indicated any increased cardiovascular risk. METHODS AND RESULTS: We used high-frequency ultrasound (22 MHz) to estimate the individual common carotid artery IMTs in 55 women at PE diagnosis and in 64 women with normal pregnancies at a similar stage. All were re-examined about 1 year postpartum. A thick intima, thin media, and high intima/media (I/M) ratio are signs of a less healthy artery wall. PE was associated with a significantly thicker mean common carotid artery intima, thinner media, and higher I/M ratio than in normal pregnancy (mean I/M difference, 0.21; 95% confidence interval, 0.17-0.25; P<0.0001). After adjustment for first trimester body mass index and mean arterial pressure, differences in intima thickness and I/M remained significant. About 1 year postpartum, these values had improved in both groups, but group differences remained significant (all adjusted P<0.0001). There were no significant differences in IMT between groups. In receiver-operating characteristic curve analysis, intima thickness and I/M were strongly predictive of prevalent PE (area under the curve, ≈0.95), whereas IMT was not (area under the curve, 0.49). CONCLUSIONS: The arteries of women with PE were negatively affected during pregnancy and 1 year postpartum compared with women with normal pregnancies, indicating increased cardiovascular risk. Estimation of intima thickness and I/M ratio seem preferable to estimation of common carotid artery IMT in imaging cardiovascular risk in PE. Results from this pilot study warrant further confirmation.

Artery wall layer dimensions during normal pregnancy: a longitudinal study using noninvasive high-frequency ultrasound.

The vascular effects of normal pregnancy were investigated by estimating the intima and media thicknesses of the common carotid artery separately using 22-MHz ultrasound (Collagenoson, Meudt, Germany) in 57 healthy women with normal pregnancies and pregnancy outcomes, in all three trimesters and at 1 yr postpartum. A thick intima, thin media, and high intima-to-media (I/M) ratio are signs of a less healthy artery wall. Mean artery wall layer dimensions remained fairly constant during pregnancy, but the intima thickness and I/M thickness ratio appeared to improve (decrease) postpartum (P < 0.001 for both). The cardiovascular risk parameters of age, body mass index, and blood pressure in the first trimester were associated with higher I/M ratios, especially in the second trimester, whereas higher serum estradiol levels were significantly associated with a lower I/M ratio. Changes from the first to second trimesters in I/M ratio, taking into account differential changes in intima and media thickness, were significantly (P < 0.05-0.001) associated with all risk parameters tested except age, which was associated with increased intima thickness (P = 0.02). Associations with third trimester values and changes from first to third trimesters were similar but less apparent. Thus, fairly constant mean artery wall layer dimensions during pregnancy appeared to improve postpartum. However, higher age, body mass index, or blood pressure and lower serum estradiol levels in the first trimester appeared to negatively affect the artery wall, strongly suggesting that pregnancy has negative vascular effects in some women. A less likely explanation involves possible adaptation to physiological changes during and after pregnancy.

Risk factors for cardiovascular disease are increased in young adults treated with stem cell transplantation during childhood.

We measured risk factors for CVD in 18 patients at a median of 18.2 yr after SCT and in sex and age-matched controls. Three patients (17%), but none of the controls, met the criteria for the MetS (p = 0.25). In the patients, we found higher levels of triglycerides (0.94 vs. 0.62 mm, p = 0.019), total cholesterol (5.1 vs. 4.0 mm, p = 0.017), LDL (3.4 vs. 2.6 mm, p = 0.019), apolipoprotein B (1.04 vs. 0.74 g/L, p = 0.004), apolipoprotein B/A1 ratio (0.7 vs. 0.5, p = 0.026), and lower levels of adiponectin (4.9 vs. 7.5 mg/L, p = 0.008) than in the controls. The patients had a lower GHmax (9 vs. 20.7 mU/L, p = 0.002). GHmax was significantly correlated inversely with triglycerides (r = -0.64, p = 0.008), total cholesterol (r = -0.61, p = 0.011), apolipoprotein B (r = -0.60, p = 0.014), and apolipoprotein B/A1 ratio (r = -0.66, p = 0.005). We recorded a significantly thicker carotid intima layer among the patients than among matched controls (0.15 vs. 0.13 mm, p = 0.034). The level of adiponectin correlated inversely with carotid intima thickness (r = -0.55, p = 0.023). After SCT in childhood, long-term survivors may be at risk of developing premature CVD.

Low-dose tibolone (1.25 mg/d) does not affect muscle strength in older women.

OBJECTIVE: More than 50% of all fractures occur in people without osteoporosis. Hormone therapy increases bone density, improves postural balance, and reduces fracture risk in postmenopausal women. It is unclear whether tibolone, a synthetic steroid hormone drug, can improve muscle strength. Thus, the aim of this study was to study the effects of low-dose tibolone therapy on muscle strength in older women. METHODS: Eighty healthy women (69 completed the study) 60 years or older were recruited through advertising in the local media. They were randomly allocated to receive either tibolone 1.25 mg/day or placebo for 6 months. The stand-up test was used to assess leg muscle strength and balance. Handgrip and leg muscle strength were measured using JAMAR and modified Cybex dynamometers. RESULTS: Baseline characteristics, including serum estradiol values and muscle strength, were similar in the two groups. Compliance with the therapy regimen was very high, averaging more than 97% in both groups. After 6 months, mean values for handgrip strength, knee extensor strength, and average time to perform 10 stands were improved numerically in both groups compared with values during baseline. However, there were no significant differences in these parameters within or between groups, and differences remained nonsignificant after adjustment for age, serum estradiol, and baseline value. CONCLUSIONS: Short-term treatment with low-dose tibolone (1.25 mg/d) seems not to affect muscle strength in older women.

Endogenous steroids measured by high-specificity liquid chromatography-tandem mass spectrometry and prevalent cardiovascular disease in 70-year-old men and women.

CONTEXT: There is a need for increased knowledge about endogenous sex hormone levels and clinical outcomes of risk/benefit. Immunoassays have poor specificity to reliably measure low steroid concentrations in elderly. OBJECTIVE: The objective of the study was to evaluate plasma steroid concentrations with regard to prevalent cardiovascular disease (CVD) in elderly, using mass spectrometry. SETTING: The study was conducted at a university hospital research unit. DESIGN AND METHODS: Plasma samples were analyzed from 202 70-yr-olds as part of a large population-based study, Prospective Investigation of the Vasculature in Uppsala Seniors. Twenty-eight of these had prevalent CVD. Eleven steroids were quantified, using liquid chromatography-tandem mass spectrometry. Women with current/previous menopausal hormone therapy (n = 35) were excluded. RESULTS: Men without prevalent CVD had higher plasma 17beta-estradiol (E2), compared with women. Men with prevalent CVD, compared with those without, had lower 17-hydroxypregnenolone (17OHPregn), 17-hydroxyprogesterone, and higher estrone/androstenedione and E2/testosterone (T) (aromatase activity). Women with prevalent CVD had lower pregnenolone, 17OHPregn, and dehydroepiandrosterone (DHEA) but higher DHEA/17OHPregn, androstenedione/DHEA, E2/T, E2/estrone, and E2/SHBG. The aromatase index, E2/T, was higher for prevalent CVD in both sexes. Adjustment for statin use, smoking, and body mass index yielded additional significant differences in men, whereas some were lost in women. Logistic regression indicated strong associations between prevalent CVD and low 17OHPregn, adjusted odds ratio of 0.18, 95% confidence interval (0.06-0.61); P = 0.006, in women and low 17-hydroxyprogesterone, 0.45 (0.25-0.80); P = 0.007 in men, most likely caused by increased throughput (consumption) toward estrogen synthesis. CONCLUSIONS: Prevalent CVD was associated with indications of lower androgen precursors, increased aromatase activity, and higher estrogen levels in both sexes. Results might represent an endogenous response to a condition of developing atherosclerosis, rather than a causative relationship. Furthermore studies are needed.

Thicker carotid intima layer, thinner media layer and higher intima/media ratio in women with recurrent depressive disorders: A pilot study using non-invasive high frequency ultrasound.

OBJECTIVES: Growing evidence indicates that depression is an important risk factor for coronary heart disease. Thus, the aim of the present study has been to investigate if young women with adolescent onset and recurrent depressive disorders have signs of carotid intima and media changes already at the age of 30. METHODS: Fifteen subjects with adolescent onset recurrent depressive disorders, mean age 31.5 years, were compared to 20 healthy women with a mean age of 39.6 years. The thickness of carotid artery intima and media was assessed, using non-invasive high-frequency ultrasound (25MHz). RESULTS: The subjects with recurrent depressive disorders had significantly thicker carotid intima, significantly thinner carotid media and significantly higher intima/media ratio despite the fact that they were about 10 years younger than the healthy women. Hypertension, obesity or smoking could not explain the results. CONCLUSION: Already at the age of 30, subjects with recurrent depressive disorders with adolescent onset do have early signs of carotid intima and media changes, indicating a less healthy artery wall, despite otherwise no clinical signs of cardiovascular disease.

Tibolone low dose (1.25 mg/d) therapy and postural balance in elderly women.

UNLABELLED: Most hip fractures occur in subjects without osteoporosis and are associated with a fall. Conventional menopausal hormone therapy (HT) improves postural balance, which might explain the rapid reduction in hip fracture risk. It is unclear whether tibolone improves postural balance, which might determine its effects on peripheral fracture risk. OBJECTIVE: To study the short-term effects of low-dose tibolone therapy on postural balance in elderly women. METHODS: Eighty healthy women (70 evaluable), aged 60 years or more, were recruited through advertising in the local media. They were randomly allocated to receive either tibolone (1.25 mg/d) or placebo for 6 months. Postural balance was assessed as sway velocity, using a force platform. RESULT(S): Baseline characteristics, including serum estradiol values and postural balance, were similar in the two study groups. On average, the overall dosing compliance was very high, over 97% in both groups. After 6 months, sway velocity had decreased (improved) by 7.6% (-0.97 cm/s; P=0.16 vs. baseline) in the tibolone arm and by 2.5% (-0.30 cm/s; P=0.59 vs. baseline) in the placebo group. The difference 0.67 cm/s was not statistically significant (95% CI -2.44, 1.10; P=0.45). Adjustments for age, serum estradiol level and variable value at baseline, revealed similar results. CONCLUSIONS: Short-term treatment with tibolone (1.25 mg/d), compared to placebo, did not significantly affect postural balance function in elderly women.

Determination of rifalazil, a potent antibacterial agent, in human plasma by liquid-liquid extraction and LC-MS/MS.

A sensitive assay for determination of rifalazil (also known as ABI-1648 and KRM-1648) in human plasma is described. The analytical method utilizes liquid-liquid extraction of plasma with methyl tert-butyl ether, followed by reversed-phase liquid chromatography with a C18 column and a mobile phase gradient utilizing 0.1% formic acid in water and acetonitrile, respectively. Electrospray mass spectrometry in the positive ion mode with selected reaction monitoring of rifalazil and an isotope labeled internal standard, 13C4-rifalazil (ABI-9901) was used for selective and sensitive detection. The calibration range was 0.050-50 ng/mL plasma using 200 microL plasma sample volume. The absolute extraction recovery of rifalazil from K2-EDTA plasma, evaluated at three concentration levels, was 88.6-97.3%, and the recovery for the internal standard was 96.8%. A study of plasma matrix effects showed a peak area response at 90-99% compared to neat solutions for both rifalazil and the internal standard. Stability evaluation of rifalazil in plasma, whole blood and methanol showed that the analyte stability was adequate when stored under study conditions. The precision, as evaluated in three validation batches, was consistent for fortified plasma quality control (QC) samples at four concentration levels, with < or =6% R.S.D. except for at the lowest quality control level where it was 10.7% R.S.D. The accuracy for QC samples (difference between found and nominal concentration) ranged from -2.3% to 5.1%. Similar precision and accuracy values were obtained over 6 months of routine application of this method. It was concluded that the performance improved markedly during routine operation by replacing a closely related structural analog internal standard with the stable isotope internal standard.

Determination of rifalazil in dog plasma by liquid-liquid extraction and LC-MS/MS: quality assessment by incurred sample analysis.

Incurred dog plasma samples were utilized for method quality assessment in this study, where a sensitive LC-MS/MS method was used for determination of the antibacterial agent rifalazil (KRM-1648 or ABI-1648). Reproducibility was estimated by repeated analysis of samples from a pharmacokinetic study, where 23 out of 864 study samples were reassayed during the course of the study. Precision for same-day duplicates was %R.S.D. 3.1 (concentration range 0.7-149 ng/ml), and over the whole study %R.S.D. 11.0 (concentration range 0.5-52 ng/ml). Moreover, standard addition experiments with incurred samples (concentration range 0.30-45 ng/ml) are described, where the recovery of spiked rifalazil amount was measured as a surrogate parameter for accuracy. The mean recovery of the added rifalazil amount was 103% (%R.S.D. 26.2). It was concluded that the described method is robust and reproducible for incurred samples. Liquid-liquid extraction was used for isolation of rifalazil and an isotope labeled internal standard from plasma. A manual procedure, based on an 8 x 12 array format, was used for sample extraction. Extracts were analyzed by reversed-phase liquid chromatography using octylsilica column with gradient elution (1mM ammonium acetate+0.01% (v/v) acetic aid in water and methanol). Mass spectrometric detection was made with positive ion electrospray ionization and LC-MS/MS analysis in a triple-quadrupole mass spectrometer. The lower limit of quantification was 50 pg/ml. MS characteristics of rifalazil are presented. In particular, two different sets of ionization and selected reaction monitoring (SRM) conditions, where in-source fragmentation was used for precursor ion formation in one of the sets, were compared. The good correlation found between the two sets of results for authentic sample extracts indicated that either condition could be used for quantification of rifalazil in dog plasma.

Altered food intake and taste perception in children with cancer after start of chemotherapy: perspectives of children, parents and nurses.

GOALS OF WORK: The purpose of this study was to better understand various variables related to food intake and eating problems in children with cancer during their chemotherapy. PATIENTS AND METHODS: Twenty-two consecutively admitted children, diagnosed with cancer and undergoing chemotherapy, participated in this study. Twenty-one of them, their parents and attending nurses participated in semi-structured interviews. Ten of the children underwent a taste acuity test, and recognition thresholds for the four basic tastes were determined. MAIN RESULTS: The shared view of both children and parents was that altered taste was the predominant cause of the eating problems. In contrast, the nurses perceived that nausea was the most important cause of the children's eating problems. In addition, psychological aspects such as learned food aversions and negative attitudes towards hospital food were regarded as important by children, parents and nurses. The taste test showed that the patients had higher thresholds for bitter taste and made more taste recognition errors compared to controls. CONCLUSIONS: Changes seem to exist both in the primary gustatory sense as well as in food perception in paediatric cancer patients undergoing chemotherapy. Single solutions, such as efforts to serve "tasty food", do not suffice alone. A more effective solution may be to combine different strategies and combinations of oral, enteral and parenteral nutrition should be considered to prevent malnutrition.

Pharmacokinetics and anticoagulant effect of the direct thrombin inhibitor melagatran following subcutaneous administration to healthy young men.

The pharmacokinetic dose linearity and reproducibility, the effects on ex-vivo coagulation time assays and bleeding time, and tolerability of the direct thrombin inhibitor melagatran following subcutaneous (s.c.) dosing were investigated in two open-label studies in healthy males: (i). a dose-escalation study in which subjects received single s.c. doses of melagatran (0.1-5 mg); and (ii). a repeated-dosing study in which 3 mg s.c. melagatran was administered at 12-h intervals for 4 days. In both studies, melagatran was rapidly absorbed with maximum plasma concentrations (C(max)) observed about 0.5 h post dosing. The half-life of melagatran was about 2 h. The area under the melagatran plasma concentration versus time curve increased linearly with dose. No time dependency in the area under the curve or Cmax was observed over 4 days of twice-daily dosing. The variability in pharmacokinetic parameters was low and the bioavailability of melagatran appeared to be complete. There was a steep and linear prolongation of thrombin time, a non-linear prolongation of both activated partial thromboplastin time and activated coagulation time, and a decrease in prothrombin complex activity with increasing melagatran plasma concentration. Only moderate increases in capillary bleeding time were observed with s.c. doses up to 5 mg melagatran. Melagatran was well tolerated after s.c. injection, with good local tolerability at the injection site.

Ximelagatran, an oral direct thrombin inhibitor, has a low potential for cytochrome P450-mediated drug-drug interactions.

BACKGROUND: Ximelagatran is an oral direct thrombin inhibitor currently in clinical development for the prevention and treatment of thromboembolic disorders. After oral administration, ximelagatran is rapidly absorbed and extensively bioconverted, via two intermediates (ethyl-melagatran and hydroxy-melagatran), to its active form, melagatran. In vitro studies have shown no evidence for involvement of cytochrome P450 (CYP) enzymes in either the bioactivation or the elimination of melagatran. OBJECTIVE: To investigate the potential of ximelagatran, the intermediates ethyl-melagatran and hydroxy-melagatran, and melagatran to inhibit the CYP system in vitro and in vivo, and the influence of three CYP substrates on the pharmacokinetics of melagatran in vivo. METHODS: The CYP inhibitory properties of ximelagatran, the intermediates and melagatran were tested in vitro by two different methods, using heterologously expressed enzymes or human liver microsomes. Diclofenac (CYP2C9), diazepam (CYP2C19) and nifedipine (CYP3A4) were chosen for coadministration with ximelagatran in healthy volunteers. Subjects received oral ximelagatran 24mg and/or diclofenac 50mg, a 10-minute intravenous infusion of diazepam 0.1 mg/kg, or nifedipine 60mg. The plasma pharmacokinetics of melagatran, diclofenac, diazepam, N-desmethyl-diazepam and nifedipine were determined when administered alone and in combination with ximelagatran. RESULTS: No inhibition, or only minor inhibition, of CYP enzymes by ximelagatran, the intermediates or melagatran was shown in the in vitro studies, suggesting that ximelagatran would not cause CYP-mediated drug-drug interactions in vivo. This result was confirmed in the clinical studies. There were no statistically significant differences in the pharmacokinetics of diclofenac, diazepam and nifedipine on coadministration with ximelagatran. Moreover, there were no statistically significant differences in the pharmacokinetics of melagatran when ximelagatran was administered alone or in combination with diclofenac, diazepam or nifedipine. CONCLUSION: As ximelagatran did not exert a significant effect on the hepatic CYP isoenzymes responsible for the metabolism of diclofenac, diazepam and nifedipine, it is reasonable to expect that it would have no effect on the metabolism of other drugs metabolised by these isoenzymes. Furthermore, the pharmacokinetics of melagatran after oral administration of ximelagatran are not expected to be altered by inhibition or induction of CYP2C9, CYP2C19 or CYP3A4. Together, the in vitro and in vivo studies indicate that metabolic drug-drug interactions involving the major human CYP enzymes should not be expected with ximelagatran.

Determination of ximelagatran, an oral direct thrombin inhibitor, its active metabolite melagatran, and the intermediate metabolites, in biological samples by liquid chromatography-mass spectrometry.

Analytical methods for the determination of ximelagatran, an oral direct thrombin inhibitor, its active metabolite melagatran, and intermediate metabolites, melagatran hydroxyamidine and melagatran ethyl ester, in biological samples by liquid chromatography (LC) positive electrospray ionization mass spectrometry (MS) using selected reaction monitoring are described. Isolation from human plasma was achieved by solid-phase extraction on octylsilica. Analytes and isotope-labelled internal standards were separated by LC utilising a C(18) analytical column and a mobile phase comprising acetonitrile-4 mmol/l ammonium acetate (35:65, v/v) containing 0.1% formic acid, at a flow-rate of 0.75 ml/min. Absolute recovery was approximately 80% for ximelagatran, approximately 60% for melagatran ethyl ester and >90% for melagatran and melagatran hydroxyamidine. Limit of quantification was 10 nmol/l, with a relative standard deviation <20% for each analyte and <5% above 100 nmol/l. Procedures for determination of these analytes in human urine and breast milk, plus whole blood from rat and mouse are also described.

Percutaneous endoscopic gastrostomy in children with malignant disease.

The objective of the study was to assess both the possible complications of percutaneous endoscopic gastrostomy (PEG) in pediatric cancer patients and its effect on weight development. The medical records of 18 children with a median age of 2.5 years (range, 0.5-14.2 years) were reviewed. The diagnoses were leukemia, central nervous system tumors, solid tumors, and lymphoma. The indications for PEG were anticipated therapy-related nutritional problems and inadequate food intake, weight loss, swallowing problems in relation to paresis of the pharynx, and relapse of the disease. Ten children received a PEG at treatment start, and eight children received it at a median time of 3.4 months (range, 0.9-27.4 months) after treatment start. The median duration of having a PEG in place was 12.3 months (range, 1.2-24.0 months). At admission the median weight for age expressed as standard deviation (SD) was -0.11 (range, -2.78-2.68). There was a significant (p =.005) decrease in the median SD from admission until PEG installation. There was also a significant increase in the median SD from the start of PEG use until 1 (p =.04) and 2 (p =.039) months after start. The most common complications were episodes of inflammation of the PEG site, which were successfully treated with topically or orally administered antibiotics, and episodes of infection, which required intravenously administered antibiotics. Taking into consideration the medical condition of the children in the study group and the considerable length of time with a PEG in place, we believe that nutrition via PEG in children with cancer has several advantages and is rarely associated with other than minor complications.

Determination of melagatran, a novel, direct thrombin inhibitor, in human plasma and urine by liquid chromatography-mass spectrometry.

Analytical methods for the determination of melagatran (H 319/68) in biological samples by liquid chromatography (LC)-positive electrospray ionization mass spectrometry using multiple reaction monitoring are described. Melagatran in plasma was isolated by solid-phase extraction on octylsilica, either in separate extraction tubes or in 96-well plates. Absolute recovery of melagatran from plasma was >92%. Melagatran and the internal standard, H 319/68 D2 13C2, were separated from other sample components by LC utilizing a C18 stationary phase and a mobile phase comprising 35% acetonitrile and 0.08% formic acid in 0.0013 mol/l ammonium acetate solution. After dilution, urine was injected directly onto the LC column and subjected to gradient LC. The relative standard deviation was 1-5% for concentrations above the limit of quantification, which was estimated for plasma at 10 or 25 nmol/l for sample volumes of 500 or 200 microl, respectively, and 100 nmol/l for urine.