POPPIE: protocol for a randomised controlled pilot trial of continuity of midwifery care for women at increased risk of preterm birth.

BACKGROUND: High rates of preterm births remain a UK public health concern. Preterm birth is a major determinant of adverse infant and longer-term outcomes, including survival, quality of life, psychosocial effects on the family and health care costs. We aim to test whether a model of care combining continuity of midwife care with rapid referral to a specialist obstetric clinic throughout pregnancy, intrapartum and the postpartum period is feasible and improves experience and outcomes for women at increased risk of preterm birth. METHODS: This pilot, hybrid, type 2 randomised controlled implementation trial will recruit 350 pregnant women at increased risk of preterm birth to a midwifery continuity of care intervention or standard care. The intervention will be provided from recruitment (antenatal), labour, birth and the postnatal period, in hospital and community settings and in collaboration with specialist obstetric clinic care, when required. Standard care will be the current maternity care provision by NHS midwives and obstetricians at the study site. Participants will be followed up until 6-8 weeks postpartum. The composite primary outcome is the appropriate initiation of any specified interventions related to the prevention and/or management of preterm labour and birth. Secondary outcomes are related to: recruitment and attrition rates; implementation; acceptability to women, health care professionals and stakeholders; health in pregnancy and other complications; intrapartum outcomes; maternal and neonatal postnatal outcomes; psycho-social health; quality of care; women's experiences and health economic analysis. The trial has 80% power to detect a 15% increase in the rate of appropriate interventions (40 to 55%). The analysis will be by 'intention to treat' analysis. DISCUSSION: Little is known about the underlying reasons why and how models of midwifery continuity of care are associated with fewer preterm births, better maternal and infant outcomes and more positive experiences; nor how these models of care can be implemented successfully in the health services. This will be the first study to provide direct evidence regarding the effectiveness, implementation and evaluation of a midwifery continuity of care model and rapid access to specialist obstetric services for women at increased risk of preterm birth. TRIAL REGISTRATION: ISRCTN37733900 . Retrospectively registered on 21 August 2017.

Integrated histopathological and urinary metabonomic investigation of the pathogenesis of microcystin-LR toxicosis.

Patterns of change of endogenous metabolites may closely reflect systemic and organ-specific toxic changes. The authors examined the metabolic effects of the cyanobacterial (blue-green algal) toxin microcystin-LR by (1)H-nuclear magnetic resonance (NMR) analysis of urinary endogenous metabolites. Rats were treated with a single sublethal dose, either 20 or 80 µg/kg intraperitoneally, and sacrificed at 2 or 7 days post dosing. Changes in the high-dose, 2-day sacrifice group included centrilobular hepatic necrosis and congestion, accompanied in some animals by regeneration and neovascularization. By 7 days, animals had recovered, the necrotizing process had ended, and the centrilobular areas had been replaced by regenerative, usually hypertrophic hepatocytes. There was considerable interanimal variation in the histologic process and severity, which correlated with the changes in patterns of endogenous metabolites in the urine, thus providing additional validation of the biomarker and biochemical changes. Similarity of the shape of the metabolic trajectories suggests that the mechanisms of toxic effects and recovery are similar among the individual animals, albeit that the magnitude and timing are different for the individual animals. Initial decreases in urinary citrate, 2-oxoglutarate, succinate, and hippurate concentrations were accompanied by a temporary increase in betaine and taurine, then creatine from 24 to 48 hours. Further changes were an increase in guanidinoacetate, dimethylglycine, urocanic acid, and bile acids. As a tool, urine can be repeatedly and noninvasively sampled and metabonomics utilized to study the onset and recovery after toxicity, thus identifying time points of maximal effect. This can help to employ histopathological examination in a guided and effective fashion.

Sexual dimorphism in urinary metabolite profiles of Han Wistar rats revealed by nuclear-magnetic-resonance-based metabonomics.

Gender-dependent metabolic variation in Han Wistar rats (n=25 male and n=25 female) was investigated using (1)H nuclear magnetic resonance (NMR) spectroscopy of urine coupled with chemometric methods. Statistically discriminatory regions of the spectra for male and female rats were identified and biomarker characterization was achieved by the further application of solid-phase extraction chromatography with NMR detection and high-performance liquid chromatography mass spectrometry. A novel discriminating molecule was identified as the sulfate conjugate of m-hydroxyphenylpropionic acid, which was excreted in higher concentrations by male rats. Other gender-related metabolite differences in the urine profiles included higher levels of trimethylamine-N-oxide, N,N'-dimethylglycine, m-hydroxyphenylpropionic acid, N-acetylglycoprotein, and cholate in samples from female animals. These studies emphasize the utility of multicomponent metabolic profiling for investigating physiological and genetic variation in experimental animals that may be of relevance to their use as models of toxicity and disease.

Metabonomics: its potential as a tool in toxicology for safety assessment and data integration.

The functional genomic techniques of transcriptomics and proteomics promise unparalleled global information during the drug development process. However, if these technologies are used in isolation the large multivariate data sets produced are often difficult to interpret, and have the potential of missing key metabolic events (e.g. as a result of experimental noise in the system). To better understand the significance of these megavariate data the temporal changes in phenotype must be described. High resolution 1H NMR spectroscopy used in conjunction with pattern recognition provides one such tool for defining the dynamic phenotype of a cell, organ or organism in terms of a metabolic phenotype. In this review the benefits of this metabonomics/metabolomics approach to problems in toxicology will be discussed. One of the major benefits of this approach is its high throughput nature and cost effectiveness on a per sample basis. Using such a method the consortium for metabonomic toxicology (COMET) are currently investigating approximately 150 model liver and kidney toxins. This investigation will allow the generation of expert systems where liver and kidney toxicity can be predicted for model drug compounds, providing a new research tool in the field of drug metabolism. The review will also include how metabonomics may be used to investigate co-responses with transcripts and proteins involved in metabolism and stress responses, such as during drug induced fatty liver disease. By using data integration to combine metabolite analysis and gene expression profiling key perturbed metabolic pathways can be identified and used as a tool to investigate drug function.

A study of metabolic compartmentation in the rat heart and cardiac mitochondria using high-resolution magic angle spinning 1H NMR spectroscopy.

High-resolution magic angle spinning (MAS) (1)H nuclear magnetic resonance (NMR) spectroscopy is increasingly being used to monitor metabolic abnormalities within cells and intact tissues. Many toxicological insults and metabolic diseases affect subcellular organelles, particularly mitochondria. In this study high-resolution (1)H NMR spectroscopy was used to examine metabolic compartmentation between the cytosol and mitochondria in the rat heart to investigate whether biomarkers of mitochondrial dysfunction could be identified and further define the mitochondrial environment. High-resolution MAS spectra of mitochondria revealed NMR signals from lactate, alanine, taurine, choline, phosphocholine, creatine, glycine and lipids. However, spectra from mitochondrial extracts contained additional well-resolved resonances from valine, methionine, glutamine, acetoacetate, succinate, and aspartate, suggesting that a number of metabolites bound within the mitochondrial membranes occur in 'NMR invisible' environments. This effect was further investigated using diffusion-weighted measurements of water and NMR spectroscopy during state 2 and state 3 respiration. State 3 respiration caused a decrease in the resonance intensity of endogenous succinate compared with state 2 respiration, suggesting that coupled respiration may also modulate the NMR detection of metabolites within mitochondria.

Investigations into biochemical changes due to diurnal variation and estrus cycle in female rats using high-resolution (1)H NMR spectroscopy of urine and pattern recognition.

Metabonomic methods utilizing (1)H NMR spectroscopy and pattern recognition analysis (NMR-PR) have been applied to investigate biochemical variation in a control population of female rats over time in relation to diurnal and estrus cycle fluctuations. Urine samples were collected twice daily (6 AM-6 PM and 6 PM-6 AM) from female rats (n = 10) for a period of 10 days. (1)H NMR spectroscopic analysis and PR were performed on each sample. Subtle differences in the endogenous metabolite excretion profiles of urine samples at the various stages of the estrus cycle were observed. The main inherent metabolic clustering in the principal components analysis (PCA) maps was related to interrat variation and was observed in the first two principal components (PCs), accounting for 66% of the variance in these data. Separation of urinary data according to time of sampling (day and night) was achieved in the lower PCs. Some of the differences in the urinary profiles of day and night samples causing this separation were attributed to the increase in metabolic activity of the rat during the night. Individual rat data were also mapped as a function of time, using PCA, to produce a metabolic trajectory, which in a number of cases facilitated separation of one or more stages of the estrus cycle. Several of the fluctuations observed between urine samples collected during the different stages of the estrus cycle may be related to hormone levels. Although variation in metabolite profiles relating to both diurnal and hormonal variation could be detected these perturbations were minor compared with the effects observed due to interrat variation. This is the first time that a hormonal cycle has been described for individuals based on NMR spectroscopic and multivariate analysis of metabolic data and shows the value of metabonomic methods in the investigation of physiological variation and rhythms.

High-resolution (1)H and (1)H-(13)C magic angle spinning NMR spectroscopy of rat liver.

High-resolution magic angle spinning (MAS) (1)H NMR spectra of small samples (ca. 8 mg) of intact rat liver are reported for the first time. One dimensional spectra reveal a number of large well-resolved NMR signals mainly from low to medium molecular weight compounds (generally <1000 Daltons) from a variety of chemical classes. A range of 2D MAS-NMR experiments were performed, including (1)H J-resolved (JRES), (1)H-(1)H total correlation spectroscopy (TOCSY) and (1)H-(13)C heteronuclear multiple quantum coherence (HMQC) to enable detailed signal assignment. Resonances were assigned from alpha- and beta-glucose, glycerol, alanine, glutamate, glycine, dimethylglycine, lysine, and threonine, together with phosphocholine, choline, lactate, trimethylamine-N-oxide (TMAO), and certain fatty acids. Well-resolved (1)H NMR signals from glycogen (poly 1-4 alpha-glucose) were observed directly in intact liver using MAS-NMR spectroscopy. In addition, the resonances from the glycogen C(1)H proton in alpha(1-->4) linked glucose units with either alpha(1-->4) units adjacent or alpha(1-->6) linked branches could be resolved in a high-resolution (1)H NMR experiment giving direct in situ information on the ratio of alpha(1-->4) to alpha(1-->6) units. This indicates that despite the relatively high MW (>1,000,000 Daltons) there is considerable segmental motion in the glycogen molecules giving long (1)H T(2) relaxation times. Magn Reson Med 44:201-207, 2000.

Pharmacokinetics and disposition of the novel dopamine agonist Z-7760 in rat after intravenous and oral administration.

1. Z-7760 (S(-)-N-[N-2-phenylethyl)-6-hexylamino]-N-propyl-5,6-dihydroxy-1,2,3,4-tetrahydro-2-naphthylamine dihydrobromide) is a potent dopamine D-1 and D-2 agonist synthesized during a search for agents to treat heart failure. Reported is the fate of the drug in rat. 2. 3H-Z-7760 was administered p.o. and i.v. to male Sprague-Dawley rats (0.4 mg and 400 microCi/kg in 0.1% ascorbic acid) and venous blood samples collected at intervals up to 48 h. Comparison of the AUC for total 3H showed that 37% of an oral dose of Z-7760 was absorbed. The percentage plasma 3H present as the parent compound fell from 82% 30 min after i.v. dosing to 12% after 24 h. After oral dosing, the fraction of plasma 3H present as unchanged Z-7760 was < 5% and this was essentially unaltered throughout the study. The long terminal elimination phase evident from 6 h was notable after both routes of administration. 3. The bile duct-cannulated rat was given 3H-Z-7760 p.o. (0.4 mg and 40 microCi/kg) and bile was collected for up to 22 h. Biliary excretion accounted for 30% of the dose. No parent compound was detected in the bile. 4. In further studies, other rats were dosed p.o. or i.v. with 3H-Z-7760 (0.4 mg and 400 microCi/kg) and urine and faeces were collected daily for 3 days. The major route of excretion was the faeces with 94-97% 3H recovered after oral and 70-73% after i.v. dosing. A further 4-7% was recovered in the urine after oral and 12-13% after i.v. dosing. 5. After oral administration of Z-7760 (100 mg/kg, 40 microCi/kg) to rats, the major metabolites in the urine were identified as the 5-O-methyl and glucuronic acid conjugates of Z-7760 by LC and MS. The glucuronide was only seen in urine after oral administration but 5-O-methyl-Z-7760 was present in urine and faeces after both routes of administration. 6. The low bioavailability of Z-7760 is the consequence of its poor absorption from the gastrointestinal tract as well as extensive first-pass metabolism that further reduces systemic blood concentrations after oral administration.

Improving primary health care for people with learning disabilities.

'Signposts for Success' (Department of Health (DoH), 1998a) states that specialist learning disability services (SpLDS) must promote liaisons with, and offer specialist advice to, primary healthcare teams (PHCTs). With the advent primary care groups (DoH, 1998b), genuine collaboration and partnership-forging is necessary and timely to prevent people with learning disabilities being excluded from healthcare services. The project described in the article had three broad aims: first, to establish a practice register of people with learning disabilities in all practices involved in the project; second, to enable practice nurses (PNs), with support, to carry out a systematic health check within the practice of people with learning disabilities; and third, to enable the project nurse to act as a crucial link between SpLDS and the PHCT. The health checks highlighted unmet health and social needs, which were then met through appropriate referral and intervention, mainly to specialist services. Follow ups were conducted to measure any health gain as a result of the applied Interventions. Evidence of health gain was revealed, pointing to the clinical effectiveness of performing such checks within the PHCTs.

The disposition of allyl isothiocyanate in the rat and mouse.

The urine was the major route of excretion of radioactivity (50-80% of dose) following the oral administration (2.5 and 25 mg/kg body weight) of allyl[14C]isothiocyanate (AITC) to male and female Fischer 344 rats and B6C3F1 mice. Smaller amounts were found in the faeces (6-12%) and expired air (3-7%). The major difference between the two species was the greater retention of radioactivity after 4 days within rats (18-24% of dose) when compared with mice (2-5% of dose). Three radioactive components were found in the urine of mice and two in rats. The three components were inorganic thiocyanate, allylthiocarbamoylmercapturic acid and allylthiocarbamoylcysteine in mice, but no cysteine conjugate was found in rat urine. In the mouse, approximately 80% of the 14C was present in the urine as the thiocyanate ion whereas in the rat some 75% was as the mercapturate. This indicates that in the mouse, hydrolysis of AITC was the major metabolic pathway whereas in the rat glutathione conjugation was the major route. A species difference was seen in the amount of [14C]AITC-derived radioactivity present in the whole blood of rats and mice; measurable levels of radioactivity remained within rat blood for a longer time period (up to 240 hr) when compared with mice (96 hr). Examination of the urinary bladders of male and female rats following oral dosing with [14C]AITC showed a sex difference with greater amounts of [14C]AITC and/or its metabolites within the bladder tissue of male rats. This data is discussed in terms of the known species- and sex-specificity of the urinary bladder tumours, which occurred after long-term administration to male rats, but not to female rats or mice of either sex, in a carcinogenicity study conducted by the National Toxicology Program in the USA.

1H and 19F-nmr spectroscopic studies on the metabolism and urinary excretion of mono- and disubstituted phenols in the rat.

1. 1H and 19F-nmr spectroscopy was used to investigate quantitatively the urinary excretion of the metabolites of 15 substituted phenols in the rat. The compounds studied were: 2-, 3-, and 4-fluorophenols; 2-, 3-, and 4-trifluoromethylphenol; 2,4-, 2,6- and 3,4-difluorophenol; 2-fluoro-5-trifluoromethylphenol, 3-fluoro-5-trifluoromethylphenol, 2-trifluoromethyl-4-fluorophenol; 3-chloro-4-fluorophenol, 3-fluoro-4-chlorophenol, and 3-methyl-4-fluorophenol. All compounds were dosed to the Sprague-Dawley rat (10 mg/kg i.p.) and urine was collected over the periods 0-8, 8-24 and 24-48 h post-dosing and analyzed using nmr spectroscopy. 2. The compounds were excreted in the urine mainly as glucuronide or sulphate conjugates or as the unchanged parent compound. There was considerable variation in the urinary excretion of the compounds over 48 h ranging from 22.1 to 93.6% of the dose. There was no apparent relationship between the molecular weight of compounds or their metabolites and the percentage molar recovery of each in the urine. 3. Ortho-substituted phenols in general showed a greater propensity for glucuronidation than did either meta- or para-substituted compounds, irrespective of the substituent group. The molar glucuronide-to-sulphate ratio for ortho-substituted compounds was found to be 2.2 +/- 0.9 whereas the ratio for both meta- and para-substituted compounds was 0.8 +/- 0.2 (p < 0.0001). 4. There were characteristic substituent effects of phenolic glucuronidation or sulphation on the 19F-nmr chemical shifts for both F- and CF3-substituted phemols and these substituent effects were a useful aid to metabolite signal assignment. 5. These studies show that nmr spectroscopy provides a rapid and convenient approach to the construction of metabolic databases of simple xenobiotics for the investigation of structure-metabolism relationships.

Prediction of urinary sulphate and glucuronide conjugate excretion for substituted phenols in the rat using quantitative structure-metabolism relationships.

1. The quantitative urinary excretion of the sulphate and glucuronide metabolites of 15 substituted phenols dosed to rat has been determined using high resolution 19F-nmr spectroscopy. 2. The urinary metabolic fate of each of the compounds was related to a series of calculated physicochemical properties for each compound to produce quantitative structure-metabolism relationships (QSMRs). Using these calculated molecular properties it was possible to predict the urinary recovery of xenobiotic material as a percentage of the administered dose, to classify the compounds according to their 'dominant' metabolite pattern and to predict quantitatively the proportions of glucuronide and sulphate conjugates in the urine by the use of multiple linear regression. 3. The quantitative predictions were tested by cross-validation and good prediction of total xenobiotic urinary recovery as a percentage of the administered dose was achieved based on an equation involving the electrophilic superdelocalizability at C4 (para to the hydroxyl function), the smallest principal ellipsoid axis dimension and the heat of formation. The largest moment of inertia and the electrophilic superdelocalizability at C3 were found to be the most significant factors for the prediction of the percentage glucuronide in the urine, and the urinary excretion of sulphate conjugates as a percentage of total urinary recovery was negatively correlated with the glucuronide excretion as little parent compound was excreted.