Views and perceptions on the designated prescribing practitioner role, barriers, and facilitators for its implementation in community pharmacy: a theory-based quantitative study

Introduction

Scottish Government aims to increase numbers of pharmacist independent prescribers (IP) in community to improve healthcare access. This includes utilising qualified IPs as Designated Prescribing Practitioners (DPP) to increase capacity to supervise pharmacists on IP courses.

Aim

To investigate views and perceptions of practice-based stakeholders and identify potential influences on DPP implementation for Scottish community pharmacists (CP)

Methods

A theory-based cross-sectional online survey of stakeholders involved in DPP role implementation (e.g. Directors of Pharmacy, Prescribing Leads, IP qualified CPs) was employed. Participation invites were shared with Scottish health boards and CP organisations via email and social media. Snowball sampling was used so no key individual was omitted. The questionnaire was informed by Royal Pharmaceutical Society (RPS) DPP Framework (1) and Consolidated Framework for Implementation Research (2). It examined views and awareness of DPP role, implementation drivers, and obstacles. The tool was reviewed for credibility and dependability then piloted. Data were analysed descriptively.

Results

Ninety-nine responses were received (NB: Since this was a national survey of multiple stakeholders without a defined sample list, response rate was indeterminate). Two-fifths (n=39, 40.2%) were community pharmacists with majority qualified for more than 10 years (n=76, 76.8%). Only 18 had previous involvement with IP courses. The table shows awareness and views of the role based on RPS framework. Respondents had positive attitudes to DPP implementation with the majority supporting it (72, 73.5%) and believing that its advantages outweigh any disadvantages (74, 75.5%). Facilitators of successful implementation were having clearly defined leadership roles (89, 90.9%), piloting (85, 87.6%), and incentives (65, 88.8%). Drivers for uptake of role included improving patient care (94, 96%) and the profession (91, 92.8%), self-development (91, 92.8%), developing individual pharmacists (89, 90.8%), payment (77, 79.4%), and being recognised by peers/employers (73, 75.2%).

Conclusion

There was positivity regarding DPP role, its acceptability in, and advantages for CP. Resource-related concerns were expressed that need further consideration to ensure effective implementation. This is the first study internationally to explore views on DPP role. Given the Scottish focus, findings may lack generalisability. Future research should focus on theory-based evaluation of structures and processes of implementation.

References

(1) Royal Pharmaceutical Society. Designated Prescribing Practitioner Competency Framework [internet]. London: Royal Pharmaceutical Society; 2019 [Cited 28/09/2021]. Available from: https://www.rpharms.com/resources/frameworks/designated-prescribing-practitioner-competency-framework

(2) Damschroder LJ, Aron DC, Keith RE, Kirsh SR, Alexander JA, Lowery JC. Fostering implementation of health services research findings into practice: a consolidated framework for advancing implementation science. Implement Sci. 2009;4:50.

Pipeline for Analyzing Activity of Metabolic Pathways in Planktonic Communities Using Metatranscriptomic Data

In this article, we present our novel pipeline for analysis of metabolic activity using a microbial community's metatranscriptome sequence data set for validation. Our method is based on expectation-maximization (EM) algorithm and provides enzyme expression and pathway activity levels. Further expanding our analysis, we consider individual enzymatic activity and compute enzyme participation coefficients to approximate the metabolic pathway activity more accurately. We apply our EM pathways pipeline to a metatranscriptomic data set of a plankton community from surface waters of the Northern Gulf of Mexico. The data set consists of RNA-seq data and respective environmental parameters, which were sampled at two depths, six times a day over multiple 24-hour cycles. Furthermore, we discuss microbial dependence on day-night cycle within our findings based on a three-way correlation of the enzyme expression during antipodal times-midnight and noon. We show that the enzyme participation levels strongly affect the metabolic activity estimates: that is, marginal and multiple linear regression of enzymatic and metabolic pathway activity correlated significantly with the recorded environmental parameters. Our analysis statistically validates that EM-based methods produce meaningful results, as our method confirms statistically significant dependence of metabolic pathway activity on the environmental parameters, such as salinity, temperature, brightness, and a few others.

A systematic review of UK-based long-term nonsurgical interventions for people with severe obesity (BMI ≥35 kg m-2 )

Introduction

The aim of this project was to systematically review UK evidence on the effectiveness of long‐term (≥12 months) weight management services (WMSs) for weight loss and weight maintenance for adults (≥16 years) with severe obesity (body mass index ≥35 kg m⁻²), who would generally be eligible for Tier 3 services.

Methods

Four data sources were searched from 1999 to October 2018.

Results

Our searches identified 20 studies, mostly noncomparative studies: 10 primary care interventions, nine in secondary care specialist weight management clinics and one commercial setting intervention. A programme including a phase of low energy formula diet (810–833 kcal day⁻¹) showed the largest mean (SD) weight change at 12 months of –12.4 (11.4) kg for complete cases, with 25.3% dropout. Limitations or differences in evaluation and reporting (particularly for denominators), unclear dropout rates, and differences between participant groups in terms of comorbidities and psychological characteristics, made comparisons between WMSs and inferences challenging.

Conclusions

There is a persistent and clear need for guidance on long‐term weight data collection and reporting methods to allow comparisons across studies and services for participants with severe obesity. Data could also include quality of life, clinical outcomes, adverse events, costs and economic outcomes. A randomised trial comparison of National Health Service Tier 3 services with commercial WMSs would be of value.

Outcomes from 18 years of cervical spine surgery in MPS IVA: a single centre's experience

PURPOSE

This study examines the long-term outcomes of paediatric Morquio (MPS IVA) patients undergoing cervical spine surgery and evaluates the factors that impacting this.

METHODS

A retrospective review was performed on all MPS IVA patients undergoing cervical spine surgery, since the introduction of standardised neuroradiological screening. The impact of preoperative neurological status, growth, genotype and radiological status on outcome is assessed, whilst long-term surgical, radiological and neurological outcomes are documented.

RESULTS

Twenty-six of the eighty-two MPS IVA patients (31%) reviewed underwent cervical spine surgery at a median age of 6.1 years (range, 1.45 to 15.24). Preoperatively, cord signal change was seen in 11 patients with 5 being myelopathic; however, 6 clinically manifesting patients had no overt cord signal change. Postoperatively, none of the 14 preoperatively clinically asymptomatic patients followed long term progressed neurologically during a median follow-up of 77.5 months (range = 18-161). Of the ten preoperatively clinically symptomatic patients who were followed up for the same duration, seven continued to deteriorate, two initially improved and one remained stable. Radiological follow-up performed for a median duration of 7 years (range = 0.5-16) has shown a degree of stenosis at the level immediately caudal to the termination of the graft in 76% of patients, though only one has become clinically symptomatic and required revision.

CONCLUSIONS

Once clinically elicitable neurological signs become evident in patients with MPS IVA, they tend to progress despite surgical intervention. Referring clinicians should also not be falsely reassured by the lack of T2 spinal cord signal change but should consider surgical intervention in the face of new clinical symptomology or radiological signs of progressive canal stenosis or instability.

Assessment and validation of a novel angiographic scoring system for peripheral artery disease

BACKGROUND

Angiography is used routinely in the assessment of lower-limb arteries, but there are few well validated angiographic scoring systems. The aim of this study was to develop and validate a novel angiographic scoring system for peripheral artery disease.

METHODS

An angiographic scoring system (the ANGIO score) was developed and applied to a sample of patients from a single vascular surgical department who underwent CT angiography of the lower limbs. The reproducibility of the ANGIO score was compared with those of the Bollinger and Trans-Atlantic inter-Society Consensus (TASC) IIb systems in a series of randomly selected patients. Associations between the ANGIO score and lower-limb ischaemia, as measured by the ankle : brachial pressure index (ABPI), and outcome events (major lower-limb amputations and cardiovascular events - myocardial infarction, stroke and cardiovascular death) were assessed.

RESULTS

Some 256 patients undergoing CT angiography were included. The interobserver reproducibility of the ANGIO score was better than that of the other scoring systems examined (κ = 0·90, P = 0·002). There was a negative correlation between the ANGIO score and ABPI (ρ = -0·33, P = 0·008). A higher ANGIO score was associated with an increased risk of major lower-limb amputation (hazard ratio (HR) for highest versus lowest tertile 9·30, 95 per cent c.i. 1·95 to 44·38; P = 0·005) and cardiovascular events (HR 2·73, 1·31 to 5·70; P = 0·007) following adjustment for established risk factors.

CONCLUSION

The ANGIO score provided a reproducible and valid assessment of the severity of lower-limb ischaemia and risk of major amputation and cardiovascular events in these patients with peripheral artery disease.

The change in position of the sciatic nerve during the posterior approach to the hip

The aim of this cadaver study was to identify the change in position of the sciatic nerve during arthroplasty using the posterior surgical approach to the hip. We investigated the position of the nerve during this procedure by dissecting 11 formalin-treated cadavers (22 hips: 12 male, ten female). The distance between the sciatic nerve and the femoral neck was measured before and after dislocation of the hip, and in positions used during the preparation of the femur. The nerve moves closer to the femoral neck when the hip is flexed to > 30° and internally rotated to 90° (90° IR). The mean distance between the nerve and femoral neck was 43.1 mm (standard deviation (sd) 8.7) with the hip at 0° of flexion and 90° IR; this significantly decreased to a mean of 36.1 mm (sd 9.5), 28.8 mm (sd 9.8) and 19.1 mm (sd 9.7) at 30°, 60° and 90° of hip flexion respectively (p < 0.001). In two hips the nerve was in contact with the femoral neck when the hip was flexed to 90°.

This study demonstrates that the sciatic nerve becomes closer to the operative field during hip arthroplasty using the posterior approach with progressive flexion of the hip.

Cite this article: Bone Joint J 2015;97-B:1056–62.

Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.

Systematic review of the clinical effectiveness and cost-effectiveness, and economic evaluation, of denosumab for the treatment of bone metastases from solid tumours

BACKGROUND

Denosumab offers an alternative, or additional, treatment for the prevention of skeletal-related events (SREs) in patients with bone metastases from solid tumours.

OBJECTIVES

The aim of this review was to assess the clinical effectiveness and cost-effectiveness of denosumab, within its licensed indication, for the prevention of SREs in patients with bone metastases from solid tumours.

DATA SOURCES

Databases searched were MEDLINE (1948 to April 2011), EMBASE (1980 to March 2011), The Cochrane Library (all sections; Issue 1, 2011) and Web of Science with Conference Proceedings (1970 to May 2011).

REVIEW METHODS

Only randomised controlled trials (RCTs) assessing denosumab, bisphosphonates (BPs) or best supportive care (BSC) in patients with bone metastases were included. Systematic reviews and observational studies were used for safety and quality-of-life assessments. Study quality was assessed using the Cochrane risk of bias tool. Studies suitable for meta-analysis were synthesised using network meta-analysis (NMA). A systematic review was conducted for cost, quality-of-life and cost-effectiveness studies. The results of this informed the cost-utility modelling. This principally estimated the cost-effectiveness of denosumab relative to zoledronic acid for when BPs are currently recommended and relative to BSC when BPs are not recommended or are contraindicated.

RESULTS

A literature search identified 39 studies (eight suitable for NMA). Denosumab was effective in delaying time to first SRE and reducing the risk of multiple SREs compared with zoledronic acid. Generally speaking, denosumab was similar to zoledronic acid for quality of life, pain, overall survival and safety. The NMA demonstrated that denosumab was more effective in delaying SREs than placebo, but was limited by numerous uncertainties. Cost-utility modelling results for denosumab relative to zoledronic acid were driven by the availability of the patient access scheme (PAS) for denosumab. Without this, denosumab was not estimated to be cost-effective compared with zoledronic acid. With it, the cost-effectiveness ranged between dominance for breast and prostate cancer, to between £5400 and £15,300 per quality-adjusted life-year (QALY) for other solid tumours (OSTs) including non-small cell lung cancer (NSCLC) and £12,700 per QALY for NSCLC. Owing to small patient gains estimated, the cost-effectiveness of denosumab was very sensitive to the zoledronic acid price. Denosumab was not estimated to be cost-effective compared with BSC.

LIMITATIONS

Only subgroup data were available for denosumab for NSCLC, and OSTs excluding NSCLC. The NMA was subject to numerous uncertainties. Owing to small patient gains estimated, the cost-effectiveness of denosumab was very sensitive to the zoledronic acid price.

CONCLUSION

Denosumab, compared with zoledronic acid and placebo, is effective in delaying SREs, but is similar with regard to quality of life and pain. Cost-effectiveness showed that without the PAS denosumab was not estimated to be cost-effective relative to either zoledronic acid or BSC. With the PAS, denosumab was estimated to be cost-effective relative to zoledronic acid but not BSC.

STUDY REGISTRATION

PROSPERO number CRD42011001418.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Elucigene FH20 and LIPOchip for the diagnosis of familial hypercholesterolaemia: a systematic review and economic evaluation

BACKGROUND

Familial hypercholesterolemia (FH) is an autosomal dominant genetic condition causing a high risk of coronary heart disease. The prevalence of this disease is about 1 in 500 in the UK, affecting about 120,000 people across the whole of the UK. Current guidelines recommend DNA testing, however, these guidelines are poorly implemented, therefore 102,000 or 85% of this group remain undiagnosed.

OBJECTIVES

To assess the diagnostic accuracy, effect on patient outcomes and cost-effectiveness of Elucigene FH20 and LIPOchip for the diagnosis of FH.

DATA SOURCES

Electronic databases including MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, BIOSIS, Science Citation Index, Conference Proceedings Citation Index - Science and Cochrane Controlled Trials Register were searched until January 2011.

REVIEW METHODS

A systematic review of the literature on diagnostic accuracy was carried out according to standard methods. An economic model was constructed to assess the cost-effectiveness of alternative diagnostic strategies for the confirmation of clinically diagnosed FH in index cases and for the identification and subsequent testing of first-, second- and possibly third-degree biological relatives of the index case. Twelve strategies were evaluated linking diagnostic accuracy to treatment outcomes and hence quality-adjusted life-years (QALYs). Deterministic and probabilistic sensitivity analyses were undertaken to investigate model and parameter uncertainty.

RESULTS

Fifteen studies were included for diagnostic accuracy; three reported Elucigene FH20, five reported LIPOchip, four reported low-density lipoprotein cholesterol (LDL-C) tests and three reported an age- and gender-specific LDL-C test against a reference standard of comprehensive genetic analysis (CGA). Sensitivity ranged from 44% to 52% for Elucigene FH20 and from 33.3% to 94.5% for various versions of LIPOchip in detecting FH-causing mutations in patients with a clinical diagnosis of FH. For LIPOchip version 10 (designed to detect 189 UK specific mutations), sensitivity would be 78.5% (based on single-centre data - Progenika, personal communication). For all other Elucigene FH20 or LIPOchip studies (apart from one LIPOchip study), specificity could not be calculated as no false-positive results could be derived from the given data. The LDL-C test was generally reported to be highly sensitive but with low specificity. For age- and gender-specific LDL-C cut-offs for cascade testing, sensitivity ranged from 68% to 96%. One UK-based study reported sensitivity of 91% and specificity of 93%. For the cost-effectiveness review, only one study reporting cost-effectiveness of any one of the comparators for this assessment was identified. Pre-screen strategies such as Elucigene FH20 followed by CGA were not cost-effective and were dominated by the single more comprehensive tests (e.g. CGA). Of the non-dominated strategies, Elucigene FH20, LIPOchip platform (Spain) and CGA were all cost-effective with associated incremental cost-effectiveness ratios (ICERs) relative to LDL-C of dominance (test is less costly and more effective), £871 and £1030 per QALY gained respectively. CGA generates the greatest QALY gain and, although other tests have lower ICERs relative to LDL-C, this is at the expense of QALY loss compared with the CGA test. Probabilistic sensitivity analysis shows that CGA is associated with an almost 100% probability of cost-effectiveness at the conventional value of willingness to pay of £20,000 per QALY gain.

LIMITATIONS

There was much uncertainty regarding the diagnostic accuracy of the included tests, with wide variation in sensitivity across reported studies. A lack of published information for the most recent version of LIPOchip created additional uncertainty, especially in relation to the chip's ability to detect copy number changes. For the economic modelling, we aimed to choose the best studies for the base-case sensitivity of the tests; however, a number of informed choices based on clinical expert opinion had to be made in the absence of published studies for a number of other parameters in the modelling. This adds some uncertainty to our results, although it is unlikely that these would be sufficient in magnitude to alter our main results and conclusions.

CONCLUSIONS

As targeted tests designed to detect a limited number of genetic mutations, Elucigene FH20 and LIPOchip cannot detect all cases of FH, in contrast with CGA. CGA is therefore the most effective test in terms of sensitivity and QALY gain, and is also highly cost-effective with an associated ICER of £1030 per QALY gain relative to current practice (LDL-C). Other tests such as Elucigene FH20 and LIPOchip are also cost-effective; however, because of inferior sensitivity compared with CGA, these tests offer cost savings but at the expense of large QALY losses compared with CGA. Further prospective multicentred studies are required to evaluate the diagnostic accuracy of new and emerging tests for FH with the LDL-C test in patients with a clinical diagnosis based on the Simon Broome criteria. Such studies should verify both test-positive and -negative results against a reference standard of CGA and should include a full economic evaluation.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Attenuated mucopolysaccharidosis type VI (Maroteaux-Lamy syndrome) due to homozygosity for the p.Y210C mutation in the ARSB gene

We describe the case of a boy recently diagnosed with an attenuated form of mucopolysacchararidosis VI (MPS VI, Maroteaux-Lamy syndrome). The Y210C mutation has not been described previously in the homozygous state, although this is a common ARSB mutation. His phenotype is essentially musculoskeletal. Urine screening tests based on measuring total GAG may miss this presentation as total GAGs were not elevated in the patient (although the electrophoresis pattern was clearly abnormal). In this phenotype the benefit of ERT remains to be established.

Advanced care planning in care homes for older people: a qualitative study of the views of care staff and families

OBJECTIVE

to explore views on advance care planning in care homes for older people.

DESIGN

qualitative exploration of views from care home staff and the family of residents in care homes for older people.

SETTING

all care homes for the elderly in two London Boroughs.

PARTICIPANTS

staff (care managers, nurses and care assistants), community nurses and families.

METHODS

individual semi-structured interviews.

RESULTS

themes of the analysis: (i)

BENEFITS

staff and family revealed positive opinions towards advance care planning. Staff felt it provided choice for residents and encouraged better planning. (ii) Barriers: staff and families perceived residents as reluctant to discuss advance care planning. Some care assistants were reluctant to be involved. Furthermore, families and staff reported prevalence of dementia among residents as another barrier. Nurses and care managers identified both family involvement and unforeseen medical circumstances as problematic. (iii) Facilitators: (a) early initiation of discussions (b) family involvement to establish preferences (c) residents and staff being well-known to each other and (d) staff training, were perceived to facilitate ACP.

CONCLUSIONS

overall, staff and families support the concept of ACP. Methods to overcome the identified barriers are required to embed ACP within end of life care in care homes.

Shear flow in smectic A liquid crystals

This paper considers the onset of a shear-induced instability in a sample of smectic A liquid crystal. Unlike many previous models, the usual director n need not necessarily coincide with the local smectic layer normal a; the traditional Oseen constraint ([Formula: see text]) is not imposed when flow is present. A recent dynamic theory for smectic A (Stewart 2007 Contin. Mech. Thermodyn. 18 343-60) will be used to examine a stationary instability in a simple model when the director reorientation and smectic layer distortions are, firstly, assumed not to be coupled to the velocity and, secondly, are supposed coupled to the velocity. A critical shear rate at which the onset of the instability occurs will be identified, together with an accompanying critical director tilt angle and critical wavenumber for the associated smectic layer undulations. Despite some critical phenomena being largely unaffected by any coupling to the flow, it will be shown that the influence of some material parameters, especially the smectic layer compression constant B(0) and the coupling constant B(1), upon the critical shear rate and critical tilt angle can be greatly affected by flow.

Genotype-phenotype correlation in Costello syndrome: HRAS mutation analysis in 43 cases

BACKGROUND

Costello syndrome (CS) is a rare multiple congenital abnormality syndrome, associated with failure to thrive and developmental delay. One of the more distinctive features in childhood is the development of facial warts, often nasolabial and in other moist body surfaces. Individuals with CS have an increased risk of malignancy, suggested to be about 17%. Recently, mutations in the HRAS gene on chromosome 11p13.3 have been found to cause CS.

METHODS

We report here the results of HRAS analysis in 43 individuals with a clinical diagnosis of CS.

RESULTS

Mutations were found in 37 (86%) of patients. Analysis of parental DNA samples was possible in 16 cases for both parents and in three cases for one parent, and confirmed the mutations as de novo in all of these cases. Three novel mutations (G12C, G12E, and K117R) were found in five cases.

CONCLUSIONS

These results confirm that CS is caused, in most cases, by heterozygous missense mutations in the proto-oncogene HRAS. Analysis of the major phenotypic features by mutation suggests a potential correlation between malignancy risk and genotype, which is highest for patients with an uncommon (G12A) substitution. These results confirm that mutation testing for HRAS is a reliable diagnostic test for CS.

Placentation in the African Elephant, Loxodonta africanus: III. Ultrastructural and Functional Features of the Placenta

Successful transfer of nutrients to the elephant fetus during pregnancy relies on a variety of placental modifications. Our light and electron microscopical investigations show that the structure is endotheliochorial from implantation to term, with unicellular, never syncytial trophoblast. Light and electron microscope immunocytochemistry shows the restriction of the glucose transporter 1 isoform to the basolateral surfaces of the trophoblast, with the glucose transporter 3 restricted to the apical plasmalemma of the trophoblast. Glucose transport to the fetus therefore requires a sequential use of both isoforms. Light and electron microscope cytochemistry indicate the presence of iron deposits only in the haemophagous zones confirming their iron transport function. No trophoblast areas with high concentrations of Calcium binding protein, specialised for Calcium transport were found. In situ hybridisation demonstrated the presence of IGF-II mRNA in the trophoblast from the earliest stage, with TGFbeta1 and HGF-SF mRNA expressed subsequently but only IGF-II and HGF mRNA present in the second half of pregnancy. The results are briefly discussed in terms of placental growth and function and indicate that the elephant placenta is another example of a unique solution to the variety of problems posed by a resident fetus.

Fetal cord plasma lipoprotein status in uncomplicated human pregnancies and in pregnancies complicated by pre-eclampsia and intrauterine growth restriction

Maternal lipids have been studied extensively in pre-eclampsia (PE) and intrauterine growth restriction (IUGR) but little is known about fetal lipids. We hypothesised that the maternal lipid perturbations in PE and IUGR pregnancies would result in similar alterations in the fetal lipid profile. We performed a cross-sectional case control study of maternal and fetal (delivery venous cord blood) lipid and lipoprotein concentrations in third trimester uncomplicated pregnancies (n = 81) and in pregnancies complicated by PE (n = 23) or IUGR (n = 17). In uncomplicated pregnancies, fetal log total cholesterol (TC), log triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) levels were significantly affected by mode of delivery. Fetal log TC (r = 0.37, P = 0.02), log TG (r = 0.34, P = 0.04) and TC/HDL-C ratio (r = 0.31, P = 0.05) were positively correlated with placental weight. Maternal TC (r = 0.35, P = 0.03) and LDL levels (r = 0.36, P = 0.02) were associated with fetal HDL-C levels. Maternal TC was significantly elevated in PE [mean 6.75 (standard deviation 1.14) mmol/L] compared to BMI-matched controls [5.94 (0.89) mmol/L P = 0.04]. In PE, fetal log TC [mean 0.36 (0.23) versus 0.11 (0.15) log mmol/L, P = 0.03], fetal log TG [-0.21 (0.32) versus -0.49 (0.26) log mmol/L, P = 0.02] and fetal TC/HDL-C ratio [3.64 (1.62) versus 1.80 (0.86), P = 0.001] were higher than in controls, after adjustment for mode of delivery. In IUGR, fetal log TG [-0.17 (0.35) versus -0.57 (0.10) log mmol/L, P = 0.01] was higher than controls, after adjustment for mode of delivery. There were no correlations between maternal and fetal lipid levels, or between fetal birth weight and either maternal or fetal lipids in the PE or IUGR groups. We conclude that although fetal lipids do not show a direct correlation with maternal lipids in PE or IUGR, these complications of pregnancy significantly impact upon fetal lipid levels possibly due to increased fetal stress or compromised placental lipid transport. Our findings are potentially pertinent to understanding the future cardiovascular health of the offspring.

Equine placentation

A tough, elastic glycoprotein capsule envelops the equine blastocyst between Days 6 and 23 after ovulation. It maintains the spherical configuration of, and provides physical support for, the embryo as it traverses the entire uterine lumen during Days 6-17, propelled by myometrial contractions that are stimulated by pulsatile release of prostaglandin F2alpha and prostaglandin E2. The capsule also accumulates constituents of the exocrine secretions of the endometrial glands ('uterine milk') as nutrients for the mobile embryo as it releases its antiluteolytic maternal recognition-of-pregnancy signal to the whole of the surface of the endometrium. Mobility ceases abruptly on Day 17 with a sudden increase in uterine tonicity that 'fixes' the conceptus at the base of one of the uterine horns. At Day 35, the trophoblast of the spherical conceptus has separated into its invasive and non-invasive components. The former, distinguished as the thickened, annulate chorionic girdle, invades the maternal endometrium to form the unique endometrial cups. These secrete a chorionic gonadotrophin that synergizes with pituitary follicle-stimulating hormone to induce secondary luteal development in the maternal ovaries. The cup cells express foreign fetal antigens that stimulate strong maternal humoral and cell-mediated immune responses, which curtail their lifespan. The non-invasive trophoblast of the allantochorion establishes a stable microvillous contact with the endometrial epithelium around Day 40 and, over the next 100 days, develops a complex multibranched interdigitation with the endometrium to form the microcotyledonary haemotrophic exchange units that cover the entire surface of the diffuse epitheliochorial placenta. Reduction in the effective total area of fetomaternal contact at this placental interface, by competition between twin conceptuses for the limited area of available endometrium, by attachment of the allantochorion to an imperfect endometrium in a mare with endometrosis, or following cross-breeding or embryo transfer between a sire and dam of dissimilar size, will all induce intrauterine growth retardation of the fetus and runting of the foal, which persists into adult life. Over 40 years ago, Professor Roger Short and his colleagues determined that the high concentrations of conventional and unique ring B unsaturated oestrogens in the blood and urine of mares during the second half of pregnancy stem from placental aromatization of large quantities of C-19 precursor molecules secreted by the temporarily hypertrophic fetal gonads. Placental production of progesterone and 5alpha-reduced progestagens, on the other hand, depends on both maternal and fetal adrenal sources of pregnenelone.

Influence of maternal size on placental, fetal and postnatal growth in the horse. I. Development in utero

The interacting influences of maternal size and fetal genotype on placental and fetal development in the mare were assessed by comparing conventional within-breed Thoroughbred (Tb-in-Tb, n = 7) and Pony (P-in-P, n = 7) control pregnancies established by artificial insemination (AI) with between-breed (Tb-in-P, n = 8; deprived in utero condition and P-in-Tb, n = 7; luxurious in utero condition) experimental pregnancies established by embryo transfer. All foals were born spontaneously and the mean (+/- SEM) duration of gestation in the two groups of control mares was significantly different (P < 0.001) at 325 +/- 3.0 days for the P-in-P pregnancies and 339 +/- 3.0 days for the Tb-in-Tb pregnancies, whereas the durations of gestation for the two experimental groups were very similar and midway between those of the control pregnancies at 332 +/- 2.8 days for the Tb-in-P and 331 +/- 2.7 days for the P-in-Tb. Mean (+/- SEM) foal birth weight and the mean (+/- SEM) values for the mass, gross area and volume of the allantochorion were all highest in the seven Tb-in-Tb pregnancies (53.1 +/- 2.6 kg, 3.8 +/- 0.3 kg, 12.9 +/- 0.3 x 10(3) cm(2), 3.5 +/- 0.2 l, respectively) and lowest in the seven P-in-P control pregnancies (24.0 +/- 1.3 kg, 1.7 +/- 0.1 kg, 8.3 +/- 0.3 x 10(3) cm(2), 1.8 +/- 0.1 l, respectively). These parameters were higher in the seven P-in-Tb pregnancies (37.9 +/- 2.1 kg, 2.7 +/- 0.1 kg, 10.1 +/- 0.5 x 10(3) cm(2), 2.5 +/- 0.1 l, respectively) than in the eight Tb-in-P (33.0 +/- 2.4 kg, 2.3 +/- 0.2 kg, 9.0 +/- 0.5 x 10(3) cm(2), 2.1 +/- 0.1 l) experimental pregnancies. Foal birth weight was positively correlated with the mass (r = 0.84, P < 0.001), gross area (r = 0.87, P < 0.001) and volume (r = 0.91, P < 0.001) of the allantochorion, and maternal weight was also positively correlated with both the mass and gross area of the allantochorion (r = 0.64 and 0.69, respectively; both P < 0.001). Application of stereology to multiple random biopsies recovered from each placenta produced mean values for the surface density of microcotyledons on the allantochorion (S(v)). Values were higher in Thoroughbred than in Pony mares regardless of the breed of fetus being carried. Multiplication of S(v) by the volume of the allantochorion to give the total microscopic area of fetomaternal contact at the placental interface was also positively correlated with foal birth weight (r = 0.84, P < 0.001). Foal birth weight was determined by the microscopic area of fetomaternal contact of the placenta and there were no differences in foal weight per m(2) of placenta regardless of fetal or maternal genomes. Thus, the results indicate that in equids, maternal size interacts with both the maternal and fetal genotypes to control the rate and extent of fetal growth by influencing the gross area of the diffuse allantochorion, and the density, complexity and depth of the microcotyledons on its surface.

Influence of maternal size on placental, fetal and postnatal growth in the horse. I. Development in utero

The interacting influences of maternal size and fetal genotype on placental and fetal development in the mare were assessed by comparing conventional within-breed Thoroughbred (Tb-in-Tb, n = 7) and Pony (P-in-P, n = 7) control pregnancies established by artificial insemination (AI) with between-breed (Tb-in-P, n = 8; deprived in utero condition and P-in-Tb, n = 7; luxurious in utero condition) experimental pregnancies established by embryo transfer. All foals were born spontaneously and the mean (+/- SEM) duration of gestation in the two groups of control mares was significantly different (P < 0.001) at 325 +/- 3.0 days for the P-in-P pregnancies and 339 +/- 3.0 days for the Tb-in-Tb pregnancies, whereas the durations of gestation for the two experimental groups were very similar and midway between those of the control pregnancies at 332 +/- 2.8 days for the Tb-in-P and 331 +/- 2.7 days for the P-in-Tb. Mean (+/- SEM) foal birth weight and the mean (+/- SEM) values for the mass, gross area and volume of the allantochorion were all highest in the seven Tb-in-Tb pregnancies (53.1 +/- 2.6 kg, 3.8 +/- 0.3 kg, 12.9 +/- 0.3 x 10(3) cm(2), 3.5 +/- 0.2 l, respectively) and lowest in the seven P-in-P control pregnancies (24.0 +/- 1.3 kg, 1.7 +/- 0.1 kg, 8.3 +/- 0.3 x 10(3) cm(2), 1.8 +/- 0.1 l, respectively). These parameters were higher in the seven P-in-Tb pregnancies (37.9 +/- 2.1 kg, 2.7 +/- 0.1 kg, 10.1 +/- 0.5 x 10(3) cm(2), 2.5 +/- 0.1 l, respectively) than in the eight Tb-in-P (33.0 +/- 2.4 kg, 2.3 +/- 0.2 kg, 9.0 +/- 0.5 x 10(3) cm(2), 2.1 +/- 0.1 l) experimental pregnancies. Foal birth weight was positively correlated with the mass (r = 0.84, P < 0.001), gross area (r = 0.87, P < 0.001) and volume (r = 0.91, P < 0.001) of the allantochorion, and maternal weight was also positively correlated with both the mass and gross area of the allantochorion (r = 0.64 and 0.69, respectively; both P < 0.001). Application of stereology to multiple random biopsies recovered from each placenta produced mean values for the surface density of microcotyledons on the allantochorion (S(v)). Values were higher in Thoroughbred than in Pony mares regardless of the breed of fetus being carried. Multiplication of S(v) by the volume of the allantochorion to give the total microscopic area of fetomaternal contact at the placental interface was also positively correlated with foal birth weight (r = 0.84, P < 0.001). Foal birth weight was determined by the microscopic area of fetomaternal contact of the placenta and there were no differences in foal weight per m(2) of placenta regardless of fetal or maternal genomes. Thus, the results indicate that in equids, maternal size interacts with both the maternal and fetal genotypes to control the rate and extent of fetal growth by influencing the gross area of the diffuse allantochorion, and the density, complexity and depth of the microcotyledons on its surface.