Abstract P1-19-02: Innovation in diagnosis and treatment of brain metastases using multifunctional nanomedicines

Systemic therapies have limited efficacy against brain metastases, largely because passive delivery of naked compounds via the bloodstream does not achieve sufficiently high or evenly dispersed intratumoural concentrations. Heterogeneous tissue architecture, abnormal perfusion, hypoxic zones and high interstitial fluid pressure are key factors limiting drug delivery, compounded by patchy blood-tumour-barrier permeability. Also, brain metastases are usually detected late, once patients become symptomatic. We are investigating whether engineered biopharmaceuticals might improve diagnostic sensitivity for earlier detection, as well as therapeutic efficacy and side-effect profiles of existing agents through active tumour targeting, delayed clearance and microenvironment-mediated activation. This study is proceeding with parallel preclinical and clinical tracks.

Preclinical aims: (1) Develop and characterise monoclonal antibody (mAb) fragments (scFvs) that target the brain metastasis markers HER2 and HER3; (2) Functionalise polyethylene glycol (PEG)-based nanocarriers with the scFvs, along with imaging agents to facilitate in vivoand ex vivoanalysis of tissue distribution; (3) Functionalise HER2/3-targeted carriers with doxorubicin via an acid-labile hydrazone bond for release in hypoxic environments, or the endosome compartment after internalization. Results to date. His-tagged HER2- and HER3-targeted scFvs based on ligand-binding sequences of clinically-approved mAbs were expressed and purified from Expi293 suspension cultures. Binding affinities are an order of magnitude stronger than parent mAbs (KD 2-8x10E-11M), determined using surface plasmon resonance analysis. The scFvs are cytostatic and moderately cytotoxic in vitro, with IC50s in order of 0.4-1.0μM. HER2 and HER3 scFvs exhibited dose-dependent, additive growth inhibition when used in combination, and induced internalisation of their receptor ligands within 4 hours in SKBr3 cells. Conclusions.The scFvs are strong carrier-tethering candidates in terms of both extracellular and intracellular payload release. Carrier synthesis is currently underway and preliminary in vivo data will be presented.

Clinical aims: (1) Develop and characterise 89Zirconium-labelled HER2-targeted PET tracers based on parent mAb and scFv; (2) Compare uptake and retention of the tracers in breast cancer patients with brain metastases; (3) Computationally relate tumour uptake to the administered dose, perfusion, tumour size and HER2 expression; (4) Determine the uptake range within and between patients, and the minimum size for reliable detection. Results to date. The mAb tracer has been synthesised, characterised and labelling processes scaled for clinical production. It is stable in physiologic conditions, retains HER2-binding activity and has a favourable biodistribution profile in NOD-SCID mice bearing BT474 xenografts. Conclusions. Australian regulatory approvals are in place and recruitment for the mAb imaging trial ("BoNSAI") has begun. Preliminary data will be presented.

Citation Format: Saunus JM, Lim M, Puttick S, Kalita-de Croft P, Houston ZH, Jones ML, Latter MJ, Campbell LC, Thomas P, Jeffree RL, Rose SE, Mahler SM, Thurecht KJ, Scott AM, Lakhani SR. Innovation in diagnosis and treatment of brain metastases using multifunctional nanomedicines [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-19-02.

Automated detection of fluorescent cells in in-resin fluorescence sections for integrated light and electron microscopy

Integrated array tomography combines fluorescence and electron imaging of ultrathin sections in one microscope, and enables accurate high-resolution correlation of fluorescent proteins to cell organelles and membranes. Large numbers of serial sections can be imaged sequentially to produce aligned volumes from both imaging modalities, thus producing enormous amounts of data that must be handled and processed using novel techniques. Here, we present a scheme for automated detection of fluorescent cells within thin resin sections, which could then be used to drive automated electron image acquisition from target regions via 'smart tracking'. The aim of this work is to aid in optimization of the data acquisition process through automation, freeing the operator to work on other tasks and speeding up the process, while reducing data rates by only acquiring images from regions of interest. This new method is shown to be robust against noise and able to deal with regions of low fluorescence.

Mineral Composition of Uroliths Obtained from Sheep and Goats with Obstructive Urolithiasis

Background

Knowledge of the mineral composition of the causative urolith is important to develop preventative strategies. Advances in analytic techniques have led to detection of urolith components not previously recognized.

Hypothesis/Objectives

The objectives of this study were to characterize uroliths in sheep and goats structurally and clinically. We hypothesized that amorphous magnesium calcium phosphate (AMCP) would be a naturally occurring urolith type in sheep and goats.

Animals

Forty‐nine sheep and goats presenting for obstructive urolithiasis from June 15, 2014 through June 14, 2016 were reviewed along with the demographic data of all small ruminants admitted during that same period.

Methods

Medical records were reviewed for demographic and historical data, and 36 uroliths obtained from these cases during diagnostic or therapeutic procedures were analyzed by infrared spectroscopy to determine chemical composition.

Results

AMCP is a naturally occurring urolith type in obstructed male sheep and goats and was the most common urolith type in this study, where it occurred as a majority component with struvite (39% of uroliths) or as a pure component (11%). Pure struvite was found in 1 urolith (2%). Calcium carbonate was the second most frequent urolith with 31% of uroliths being pure calcium carbonate.

Conclusions and Clinical Importance

This study demonstrates that uroliths, which appear consistent with struvite, could actually be calcium‐containing AMCP. Urolith analysis is critical in determining mineral content of uroliths to guide dietary recommendations for prevention.

Immunosuppressive human anti-CD83 monoclonal antibody depletion of activated dendritic cells in transplantation

Current immunosuppressive/anti-inflammatory agents target the responding effector arm of the immune response and their nonspecific action increases the risk of infection and malignancy. These effects impact on their use in allogeneic haematopoietic cell transplantation and other forms of transplantation. Interventions that target activated dendritic cells (DCs) have the potential to suppress the induction of undesired immune responses (for example, graft versus host disease (GVHD) or transplant rejection) and to leave protective T-cell immune responses intact (for example, cytomegalovirus (CMV) immunity). We developed a human IgG1 monoclonal antibody (mAb), 3C12, specific for CD83, which is expressed on activated but not resting DC. The 3C12 mAb and an affinity improved version, 3C12C, depleted CD83(+) cells by CD16(+) NK cell-mediated antibody-dependent cellular cytotoxicity, and inhibited allogeneic T-cell proliferation in vitro. A single dose of 3C12C prevented human peripheral blood mononuclear cell-induced acute GVHD in SCID mouse recipients. The mAb 3C12C depleted CMRF-44(+)CD83(bright) activated DC but spared CD83(dim/-) DC in vivo. It reduced human T-cell activation in vivo and maintained the proportion of CD4(+) FoxP3(+) CD25(+) Treg cells and also viral-specific CD8(+) T cells. The anti-CD83 mAb, 3C12C, merits further evaluation as a new immunosuppressive agent in transplantation.

Lactobacillus fermentum NCIMB 5221 and NCIMB 2797 as cholesterol-lowering probiotic biotherapeutics: in vitro analysis

Cardiovascular and coronary artery disease risk are correlated with cholesterol levels and are significant health concerns. Current cholesterol-lowering approaches includes lifestyle and diet modifications, as well as statins which presents numerous shortcomings. The probiotic bacteria, Lactobacillus fermentum NCIMB 5221 and NCIMB 2797, have demonstrated cholesterol-lowering potential in animal studies. However, there is a lack in understanding the mechanism(s) behind these observed effects. The goal of this work is to investigate, in vitro, the cholesterol-lowering mechanisms of these two strains. To determine the cholesterol-lowering mechanisms, probiotic cholesterol assimilation, colon epithelial adhesion and inhibition of cholesterol uptake by colon epithelial (Caco-2) cells were investigated. L. fermentum NCIMB 2797 (P=0.012) and NCIMB 5221 (P=0.003) assimilated cholesterol and their cell surface hydrophobicity was 70.30±8.85% and 55.60±2.59%, respectively. Both L. fermentum strains showed no significant impact (P>0.05) on Caco-2 cell viability. Of most interest, Caco-2 pre-exposure to L. fermentum NCIMB 5221 significantly decreased (P=0.015) cholesterol uptake, with 85.98±2.07% uptake compared to the untreated cells. Similarly, L. fermentum NCIMB 2797 probiotic cells significantly decreased (P=0.019) cholesterol uptake by Caco-2 cells, with 86.45±1.71% uptake observed compared to the control cells. The results demonstrate that L. fermentum NCIMB 5221 and L. fermentum NCIMB 2797 have the potential via various modes of action to lower cholesterol. Additional studies are required to understand the mechanism(s) of action behind probiotic cholesterol assimilation and behind the cholesterol uptake inhibition by colon epithelial cells.

Use of next-generation sequencing and candidate gene analysis to identify underlying defects in patients with inherited platelet function disorders

BACKGROUND

Inherited platelet function disorders (PFDs) are heterogeneous, and identification of the underlying genetic defects is difficult when based solely on phenotypic and clinical features of the patient.

OBJECTIVE

To analyze 329 genes regulating platelet function, number, and size in order to identify candidate gene defects in patients with PFDs.

PATIENTS/METHODS

Targeted analysis of candidate PFD genes was undertaken after next-generation sequencing of exomic DNA from 18 unrelated index cases with PFDs who were recruited into the UK Genotyping and Phenotyping of Platelets (GAPP) study and diagnosed with platelet abnormalities affecting either Gi signaling (n = 12) or secretion (n = 6). The potential pathogenicity of candidate gene defects was assessed using computational predictive algorithms.

RESULTS

Analysis of the 329 candidate PFD genes identified 63 candidate defects, affecting 40 genes, among index cases with Gi signaling abnormalities, while 53 defects, within 49 genes, were identified among patients with secretion abnormalities. Homozygous gene defects were more commonly associated with secretion abnormalities. Functional annotation analysis identified distinct gene clusters in the two patient subgroups. Thirteen genes with significant annotation enrichment for 'intracellular signaling' harbored 16 of the candidate gene defects identified in nine index cases with Gi signaling abnormalities. Four gene clusters, representing 14 genes, with significantly associated gene ontology annotations were identified among the cases with secretion abnormalities, the most significant association being with 'establishment of protein localization.'

CONCLUSION

Our findings demonstrate the genetic complexity of PFDs and highlight plausible candidate genes for targeted analysis in patients with platelet secretion and Gi signaling abnormalities.

Rare platelet GPCR variants: what can we learn?

Platelet-expressed GPCRs are critical regulators of platelet function. Pharmacological blockade of these receptors forms a powerful therapeutic tool in the treatment and prevention of arterial thrombosis associated with coronary atherosclerosis and ischaemic stroke. However, anti-thrombotic drug therapy is associated with high inter-patient variability in therapeutic response and adverse bleeding side effects. In order to optimize the use of existing anti-platelet drugs and to develop new therapies, more detailed knowledge is required relating to the molecular mechanisms that regulate GPCR and therefore platelet function. One approach has been to identify rare, function-disrupting mutations within key platelet proteins in patients with bleeding disorders. In this review, we describe how an integrated functional genomics strategy has contributed important structure-function information about platelet GPCRs with specific emphasis upon purinergic and thromboxane A2 receptors. We also discuss the potential implications these findings have for pharmacotherapy and for understanding the molecular basis of mild bleeding disorders.

What is the value of routinely testing full blood count, electrolytes and urea, and pulmonary function tests before elective surgery in patients with no apparent clinical indication and in subgroups of patients with common comorbidities: a systematic review of the clinical and cost-effective literature

BACKGROUND

The evidence base which supported the National Institute for Health and Clinical Excellence (NICE) published Clinical Guideline 3 was limited and 50% was graded as amber. However, the use of tests as part of pre-operative work-up remains a low-cost but high-volume activity within the NHS, with substantial resource implications. The objective of this study was to identify, evaluate and synthesise the published evidence on the clinical effectiveness and cost-effectiveness of the routine use of three tests, full blood counts (FBCs), urea and electrolytes tests (U&Es) and pulmonary function tests, in the pre-operative work-up of otherwise healthy patients undergoing minor or intermediate surgery in the NHS.

OBJECTIVE

The aims of this study were to estimate the clinical effectiveness and cost-effectiveness of routine pre-operative testing of FBC, electrolytes and renal function and pulmonary function in adult patients classified as American Society of Anaesthesiologists (ASA) grades 1 and 2 undergoing elective minor (grade 1) or intermediate (grade 2) surgical procedures; to compare NICE recommendations with current practice; to evaluate the cost-effectiveness of mandating or withdrawing each of these tests in this patient group; and to identify the expected value of information and whether or not it has value to the NHS in commissioning further primary research into the use of these tests in this group of patients.

DATA SOURCES

The following electronic bibliographic databases were searched: (1) BIOSIS; (2) Cumulative Index to Nursing and Allied Health Literature; (3) Cochrane Database of Systematic Reviews; (4) Cochrane Central Register of Controlled Trials; (5) EMBASE; (6) MEDLINE; (7) MEDLINE In-Process & Other Non-Indexed Citations; (8) NHS Database of Abstracts of Reviews of Effects; (9) NBS Health Technology Assessment Database; and (10) Science Citation Index. To identify grey and unpublished literature, the Cochrane Register of Controlled Trials, National Research Register Archive, National Institute for Health Research Clinical Research Network Portfolio database and the Copernic Meta-search Engine were searched. A large routine data set which recorded the results of tests was obtained from Leeds Teaching Hospitals Trust.

REVIEW METHODS

A systematic review of the literature was carried out. The searches were undertaken in March to April 2008 and June 2009. Searches were designed to retrieve studies that evaluated the clinical effectiveness and cost-effectiveness of routine pre-operative testing of FBC, electrolytes and renal function and pulmonary function in the above group of patients. A postal survey of current practice in testing patients in this group pre-operatively was undertaken in 2008. An exemplar cost-effectiveness model was constructed to demonstrate what form this would have taken had there been sufficient data. A large routine data set that recorded the results of tests was obtained from Leeds Teaching Hospitals Trust. This was linked to individual patient data with surgical outcomes, and regression models were estimated.

RESULTS

A comprehensive and systematic search of both the clinical effectiveness and cost-effectiveness literature identified a large number of potentially relevant studies. However, when these studies were subjected to detailed review and quality assessment, it became clear that the literature provides no evidence on the clinical effectiveness and cost-effectiveness of these specific tests in the specific patient groups. The postal survey had a 17% response rate. Results reported that in ASA grade 1, patients aged < 40 years with no comorbidities undergoing minor surgery did not have routine tests for FBC, electrolytes and renal function and pulmonary function. The results from the regression model showed that the frequency of test use was not consistent with the hypothesis of their routine use. FBC tests were performed in only 58% of patients in the data set and U&E testing was carried out in only 57%.

LIMITATIONS

Systematic searches of the clinical effectiveness and cost-effectiveness literature found that there is no evidence on the clinical effectiveness or cost-effectiveness of these tests in this specific clinical context for the NHS. A survey of NHS hospitals found that respondent trusts were implementing current NICE guidance in relation to pre-operative testing generally, and a de novo analysis of routine data on test utilisation and post-operative outcome found that the tests were not be used in routine practice; rather, use was related to an expectation of a more complex clinical case. The paucity of published evidence is a limitation of this study. The studies included relied on non-UK health-care systems data, which may not be transferable. The inclusion of non-randomised studies is associated with an increased risk of bias and confounding. Scoping work to establish the likely mechanism of action by which tests would impact upon outcomes and resource utilisation established that the cause of an abnormal test result is likely to be a pivotal determinant of the cost-effectiveness of a pre-operative test and therefore evaluations would need to consider tests in the context of the underlying risk of specific clinical problems (i.e. risk guided rather than routine use).

CONCLUSIONS

The time of universal utilisation of pre-operative tests for all surgical patients is likely to have passed. The evidence we have identified, though weak, indicates that tests are increasingly utilised in patients in whom there is a reason to consider an underlying raised risk of a clinical abnormality that should be taken into account in their clinical management. It is likely that this strategy has led to substantial resource savings for the NHS, although there is not a published evidence base to establish that this is the case. The total expenditure on pre-operative tests across the NHS remains significant. Evidence on current practice indicates that clinical practice has changed to such a degree that the original research question is no longer relevant to UK practice. Future research on the value of these tests in pre-operative work-up should be couched in terms of the clinical effectiveness and cost-effectiveness in the identification of specific clinical abnormalities in patients with a known underlying risk. We suggest that undertaking a multicentre study making use of linked, routinely collected data sets would identify the extent and nature of pre-operative testing in this group of patients.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Effect of castration method on neurohormonal and electroencephalographic stress indicators in Holstein calves of different ages

As public concern for food animal welfare increases, a need to validate objective pain assessment tools exists in order to formulate animal welfare policies and facilitate regulatory approval of compounds to alleviate pain in livestock in the United States. The aims of this study were (1) to compare the physiological response to pain induced by surgical and nonsurgical (band) castration in calves and (2) to elucidate age-related differences in pain response of calves subjected to different castration methods. Seventy-six Holstein bull calves were blocked by age (≤8-wk and ≥6-mo-old) and randomly assigned to 1 of 4 treatment groups: control (n=20), castration by banding (n=18), cut-and-clamp surgical castration (n=20), and cut-and-pull surgical castration (n=18). Measurements included electroencephalogram, heart rate variability, infrared thermography, electrodermal activity, and concentrations of serum cortisol and plasma substance P before, during, and within 20min following castration. Electroencephalogram recordings showed desynchronization for all treatments, consistent with increased arousal; yet the magnitude of desynchronization was greatest for 6-mo-old calves castrated by cut-and-clamp. Additionally, older calves in the cut-and-pull group showed greater desynchronization than younger calves in the same group. Based on the heart rate variability analysis, 6-mo-old calves in the control or cut-and-pull castration groups showed greater sympathetic tone than younger calves in the same treatment groups. Overall, younger calves showed lower electrodermal activity than older calves. Regardless of treatment, concentrations of cortisol and plasma substance P were greater in 6-mo-old calves relative to their younger counterparts, indicating a more robust response to all treatments in older calves. In summary, neurohormonal and electroencephalographic stress responses of calves to castration were age-specific. Castration by cut-and-clamp showed the most pronounced stress response in 6-mo-old calves. These findings provide evidence that support welfare policies recommending castration at an early age and the use of analgesic compounds at the time of surgical castration especially in older calves. However, the potential long-term negative consequences of early untreated pain must be considered and warrant further investigation.

Platelet dysfunction associated with the novel Trp29Cys thromboxane A₂ receptor variant

BACKGROUND

Genetic variations that affect the structure of the thromboxane A2 receptor (TP receptor) provide insights into the function of this key platelet and vascular receptor, but are very rare in unselected populations.

OBJECTIVES

To determine the functional consequences of the TP receptor Trp29Cys (W29C) substitution.

PATIENTS/METHODS

We performed a detailed phenotypic analysis of an index case (P1) with reduced platelet aggregation and secretion responses to TP receptor pathway activators, and a heterozygous TP receptor W29C substitution. An analysis of the variant W29C TP receptor expressed in heterologous cells was performed.

RESULTS

Total TP receptor expression in platelets from P1 was similar to that of controls, but there was reduced maximum binding and reduced affinity of binding to the TP receptor antagonist [(3) H]SQ29548. HEK293 cells transfected with W29C TP receptor cDNA showed similar total TP receptor expression to wild-type (WT) controls. However, the TP receptor agonist U46619 was less potent at inducing rises in cytosolic free Ca(2+) in HEK293 cells expressing the W29C TP receptor than in WT controls, indicating reduced receptor function. Immunofluorescence microscopy and cell surface ELISA showed intracellular retention and reduced cell surface expression of the W29C TP receptor in HEK293 cells. Consistent with the platelet phenotype, both maximum binding and the affinity of binding of [(3) H]SQ29548 to the W29C TP receptor were reduced compared to WT controls.

CONCLUSION

These findings extend the phenotypic description of the very rare disorder TP receptor deficiency, and show that the W29C substitution reduces TP receptor function by reducing surface receptor expression and by disrupting ligand binding.

Bilateral buphthalmia in a 4-month-old Texas longhorn steer

Congenital ocular disease occurs uncommonly in cattle, with multiple abnormalities reported only sporadically in the literature. This report describes a case of anterior segment dysgenesis resulting in glaucoma in a 4-month-old Texas Longhorn steer. On clinical exam, bilateral buphthalmia was present and intraocular pressures exceeded 47 mm Hg in both eyes. On histopathologic examination, the iridocorneal angle and filtration apparatus were distorted due to collapse of the ciliary cleft and anterior displacement of the anterior portion of the ciliary body. No evidence of inflammation or other causes of glaucoma were recognized.

School-linked sexual health services for young people (SSHYP): a survey and systematic review concerning current models, effectiveness, cost-effectiveness and research opportunities

BACKGROUND

Report based on a service-mapping study and a systematic review concerning sexual health services for young people, either based in or closely linked to schools.

OBJECTIVES

To identify current forms of school-based sexual health services (SBSHS) and school-linked sexual health services (SLSHS) in the UK, review and synthesise existing evidence from qualitative and quantitative studies concerning the effectiveness, acceptability and cost-effectiveness of these types of service and to identify potential areas for further research.

DATA SOURCES

Electronic databases were searched from 1985 onwards. For published material: the Cochrane Library (1991-), MEDLINE, PREMEDLINE (2007-), CINAHL, EMBASE, AMED, ASSIA (1987-), IBSS, ERIC, PsycINFO, Science Citation Index (SCI) and Social Sciences Citation Index. For unpublished material and grey literature: the Social Care Institute of Excellence Research Register; the National Research Register (1997-), ReFeR; Index to Theses, and HMIC.

REVIEW METHODS

A service-mapping questionnaire was circulated to school nurses in all parts of the UK, and semistructured telephone interviews with service coordinators in NHS and local authority (LA) roles were conducted. An evidence synthesis was performed based on a systematic review of the quantitative evidence about service effectiveness, qualitative evidence about user and professional views and a mixed-methods synthesis. A proof-of-concept model for assessing cost-effectiveness was drawn up.

RESULTS

Three broad types of UK sexual health service provision were identified. Firstly, SBSHS staffed by school nurses, offering 'minimal' or 'basic' levels of service. Secondly, SBSHS and SLSHS staffed by a multiprofessional team, but not medical practitioners, offering 'basic' or 'intermediate' levels of service. Thirdly, SBSHS and SLSHS staffed by a multiprofessional team, including medical practitioners offering 'intermediate' or 'comprehensive' levels of service. The systematic review showed that SBSHS are not associated with higher rates of sexual activity among young people, nor with an earlier age of first intercourse. There was evidence to show positive effects in terms of reductions in births to teenage mothers, and in chlamydial infection rates among young men, although this evidence coming primarily from the USA. Therefore, the findings need to be tested in relation to UK-based services. Also evidence to suggest that broad-based, holistic service models, not restricted to sexual health, offer the strongest basis for protecting young people's privacy and confidentiality, countering perceived stigmatisation, offering the most comprehensive range of products and services, and maximising service uptake. Findings from the mapping study also indicate that broad-based services, which include medical practitioner input within a multiprofessional team, meet the stated preferences of staff and of young people most clearly. Partnership-based developments of this kind also conform to the broad policy principles embodied in the Every Child Matters framework in the UK and allied policy initiatives. However, neither these service models nor narrower ones have been rigorously evaluated in terms of their impact on the key outcomes of conception rates and sexually transmitted infection (STI) rates, in the UK or in other countries. Therefore, appropriate data were not found to support cost-effectiveness modelling.

LIMITATIONS

Low response rate to the questionnaire. Scotland, Wales and Northern Ireland were under-represented. Also, the distinction made in the questionnaire between 'general health' and 'sexual health' services did not prove robust.

CONCLUSIONS

There is no single, dominant service model in the UK. The systematic review demonstrated that the evidence base for these services remains limited and uneven, and draws largely on US studies. Qualitative research is needed to develop robust process and outcome indicators for the evaluation of SLSHS/SBSHS in the UK. These indicators could then be used both in local evaluations, and in large, longitudinal studies of service effectiveness and cost-effectiveness. Future research should examine the impact of the differing types of services currently evolving in the UK, encompassing school-based and school-linked models, as well as models with and without medical practitioner involvement.

Effect of nitrogen supplementation and zilpaterol-HCl on urea kinetics in steers consuming corn-based diets

We studied effects of zilpaterol-HCl on steers consuming corn-based diets with nitrogen (N) supplementation provided by dried distillers grains with solubles (DDGS) or urea. Two sets of six steers (approximately 350 kg) were used in two replicates of similarly designed trials. Within each replicate, three steers were fed 60 mg/day of zilpaterol-HCl throughout the trial and three steers received no zilpaterol-HCl. Within zilpaterol treatment, three corn-based dietary N treatments were offered in Latin square designs: control (9.6% crude protein), urea (UREA; 12.4% crude protein) or DDGS (13.7% crude protein). Total feed intake was unexpectedly greater (p < 0.01) with zilpaterol feeding but was not affected by dietary N (p = 0.76). Nitrogen intake was greater (p < 0.01) when zilpaterol was fed and was greater (p < 0.05) for DDGS and UREA than for control. Despite greater N intake, zilpaterol did not affect urea entry rate (p = 0.80) or urea-N recycled to the gastrointestinal tract (GER; p = 0.94). As a percentage of N intake, urea entry rate (p = 0.19) tended to be less when zilpaterol was fed (91 vs. 123% of N intake), and GER was numerically (p = 0.34) less (72 vs. 92% of N intake). Microbial N flow was greater (p = 0.02) for zilpaterol than for control but did not differ (p = 0.78) among dietary N treatments. As a percentage of N intake, microbial N flow was unaffected by zilpaterol (p = 0.97), but was greater (p < 0.05) for control than DDGS or UREA. The lack of change in urea entry and GER in response to zilpaterol, despite greater N intake, as well as lower urea entry and GER when expressed as proportions of N intake provide some evidence that the amount of N available for urea production and recycling was reduced by zilpaterol.

Hemoglobin Kinetics of the Galapagos Rift Vent Tube Worm Riftia pachyptila Jones (Pogonophora; Vestimentifera)

Kinetics of the reactions of Riftia pachyptila hemoglobin with oxygen were followed spectrophotometrically by stopped-flow and laser flash photolysis techniques. The rate of oxygen dissociation increases eightfold over the range of 5 degrees to 20 degrees C (k = 2.2 sec(-1)at 10 degrees C). Oxygen recombination after flash photolysis was biphasic. The rates of both slow and fast phases of the reaction were independent of temperature from 0 degrees to 20 degrees C(k'fast = 7 x 10(6); k'slow = 1 x 16(6) liter mole (-1) sec(-1)). As the oxygen affinity is relatively temperature independent, analysis in terms of the two-state model of cooperativity requires that the conformational equilibrium constant L decrease by about 50-fold between 3 degrees and 15 degrees C.

Prokaryotic Cells in the Hydrothermal Vent Tube Worm Riftia pachyptila Jones: Possible Chemoautotrophic Symbionts

The existence of a symbiotic association between vestimentiferan tube worms from deep-sea hydrothermal vents and chemoautotrophic sulfur-oxidizing prokaryotes, based on histological and enzymatic evidence, is suggested.

RGD-ligand mimetic antagonists of integrin alphaIIbbeta3 paradoxically enhance GPVI-induced human platelet activation

BACKGROUND

The integrin alpha(IIb)beta(3) is the major mediator of platelet aggregation and has, therefore, become an important target of antithrombotic therapy. Antagonists of alpha(IIb)beta(3), for example abciximab, tirofiban and eptifibatide, are used in the treatment of acute coronary syndromes. However, in addition to effective blockade of the integrin, binding of can induce conformational changes in the integrin and can also induce integrin clustering. This class effect of RGD-ligand mimetics might, therefore, underlie paradoxical platelet activation and thrombosis previously reported.

OBJECTIVES

To examine the components of signaling pathways and functional responses in platelets that may underlie this phenomenon of paradoxical platelet activation.

METHODS

We assessed the effect of lotrafiban, and other alpha(IIb)beta(3) antagonists including the clinically used drug tirofiban, on tyrosine phosphorylation of key signaling proteins in platelets by immunoblotting and also platelet functional outputs such as cytosolic calcium responses, phosphatidylserine exposure (pro-coagulant activity) and dense granule release.

RESULTS

In all cases, no effect of alpha(IIb)beta(3) antagonists were observed on their own, but these integrin antagonists did lead to a marked potentiation of glycoprotein VI (GPVI)-associated FcR gamma-chain phosphorylation, activation of Src family kinases and Syk kinase. This correlated with increased dense granule secretion, cytosolic calcium response and exposure of phosphatidylserine on the platelet surface. P2Y(12) antagonism abolished the potentiated phosphatidylserine exposure and dense granule secretion but not the cytosolic calcium response.

CONCLUSIONS

These data provide a mechanism for enhancement of platelet activity by alpha(IIb)beta(3) inhibitors, but also reveal a potentially important signaling pathway operating from the integrin to GPVI signaling.

Alteplase for the treatment of acute ischaemic stroke: a single technology appraisal

This paper presents a summary of the evidence review group report into the clinical effectiveness and cost-effectiveness of alteplase for the treatment of acute ischaemic stroke, in accordance with the licensed indication, based upon the evidence submission from the manufacturer to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The submitted clinical evidence included several randomised controlled trials indicating that, in highly selected patients, alteplase administered at a licensed dose within 3 hours of the onset of acute ischaemic stroke is associated with a statistically significant reduction in the risk of death or dependency at 3 months compared with placebo, despite a significantly increased risk of symptomatic intracranial haemorrhage within the first 7-10 days. Data from the National Institute of Neurological Disorders and Stroke (NINDS) trial suggest that the benefit of treatment is sustained at 6 and 12 months. However, data from observational studies suggest that few patients with acute ischaemic stroke will be eligible for alteplase therapy under the terms of the current licensing agreement. In particular, many patients will be excluded by virtue of their age, and many more by the restriction of therapy to patients in whom treatment can be initiated within 3 hours of symptom onset. The manufacturer's submission included a state transition model evaluating the impact of treatment with alteplase within 3 hours of onset of stroke symptoms compared to standard treatment reporting that, in the base-case analysis, alteplase was both less costly and more effective than standard treatment. This increased to a maximum of approximately 4000 pounds upon one-way sensitivity analysis of the parameters. The probabilistic sensitivity analysis presented within the submission suggests that the probability that alteplase has a cost-effectiveness ratio greater than 20,000 pounds per quality-adjusted life-year (QALY) gained is close to 1 (0.99). The results of the short-term model demonstrate that alteplase is cost-effective over a 12-month period, with an incremental cost-effectiveness ratio of 14,026 pounds per QALY gained. This increased to a maximum of 50,000 pounds upon one-way sensitivity analysis of the parameters. At 12 months, the probabilistic sensitivity analysis presented within the submission suggests that the probability that alteplase has a cost-effectiveness ratio greater than 20,000 pounds per QALY gained is approximately 0.7. The guidance issued by NICE in April 2007 as a result of the STA states that alteplase is recommended for the treatment of acute ischaemic stroke only when used by physicians trained and experienced in the management of acute stroke and in centres with the required facilities.

Docetaxel for the adjuvant treatment of early node-positive breast cancer: a single technology appraisal

This paper presents a summary of the evidence review group (ERG) report into the clinical and cost-effectiveness of docetaxel for the adjuvant treatment of early node-positive breast cancer based upon the manufacturer's submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The manufacturer's scope restricts the intervention to docetaxel in combination with doxorubicin and cyclophosphamide (TAC), and the comparator to anthracycline-based chemotherapy. Based on the BCIRG 001 trial, the submitted evidence shows that TAC is associated with superior disease-free and overall survival at 5 years compared with the anthracycline-based regimen FAC. The absolute risk reduction in patients treated with TAC compared with those treated with FAC was 7% for disease-free survival and 6% for overall survival. However, TAC was associated with significantly greater toxicity than FAC. There is also evidence that docetaxel, in an unlicensed sequential regimen FEC100-T, is associated with superior disease-free and overall survival at 5 years compared with FEC100. An economic model was developed by the manufacturer based on the BCIRG 001 trial. This generated central estimates of the cost per life-year gained and cost per quality-adjusted life-year (QALY) gained of TAC compared with FAC of 7900 pounds and 9800 pounds respectively. The manufacturer's submission predicts a cost-effectiveness of 15,000 pounds to 20,000 pounds per QALY gained for TAC compared with E-CMF (epirubicin in sequential therapy with cyclophosphamide, methotrexate, and fluorouracil), and estimates the cost-effectiveness of FEC100-T to be 8200 pounds per QALY compared with FEC100. Taking into account a number of issues identified by the ERG this may generate higher estimates of cost-effectiveness, but these are unlikely to exceed 35,000 pounds per QALY gained. Importantly, FAC is not commonly used in clinical practice in the UK and, therefore, the submitted evidence does not indicate whether TAC is superior to the anthracycline-based regimens that are in common use (FEC or E-CMF). The indirect comparisons presented suggest that the economic case for TAC in comparison to current UK practice may not be proven. The manufacturer's submission failed to record evidence of three serious adverse events in patients receiving docetaxel with doxorubicin or to mention the concern of the European Medicines Agency regarding TAC's long-term adverse events. The guidance issued by NICE in June 2006 as a result of the STA states that docetaxel, when given concurrently with doxorubicin and cyclophosphamide (the TAC regimen), is recommended as an option for the adjuvant treatment of women with early node-positive breast cancer.

Alteplase for the treatment of acute ischaemic stroke: a single technology appraisal

This paper presents a summary of the evidence review group report into the clinical effectiveness and cost-effectiveness of alteplase for the treatment of acute ischaemic stroke, in accordance with the licensed indication, based upon the evidence submission from the manufacturer to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The submitted clinical evidence included several randomised controlled trials indicating that, in highly selected patients, alteplase administered at a licensed dose within 3 hours of the onset of acute ischaemic stroke is associated with a statistically significant reduction in the risk of death or dependency at 3 months compared with placebo, despite a significantly increased risk of symptomatic intracranial haemorrhage within the first 7–10 days. Data from the National Institute of Neurological Disorders and Stroke (NINDS) trial suggest that the benefit of treatment is sustained at 6 and 12 months. However, data from observational studies suggest that few patients with acute ischaemic stroke will be eligible for alteplase therapy under the terms of the current licensing agreement. In particular, many patients will be excluded by virtue of their age, and many more by the restriction of therapy to patients in whom treatment can be initiated within 3 hours of symptom onset. The manufacturer’s submission included a state transition model evaluating the impact of treatment with alteplase within 3 hours of onset of stroke symptoms compared to standard treatment reporting that, in the base-case analysis, alteplase was both less costly and more effective than standard treatment. This increased to a maximum of approximately £4000 upon one-way sensitivity analysis of the parameters. The probabilistic sensitivity analysis presented within the submission suggests that the probability that alteplase has a cost-effectiveness ratio greater than £20,000 per quality-adjusted life-year (QALY) gained is close to 1 (0.99). The results of the short-term model demonstrate that alteplase is cost-effective over a 12-month period, with an incremental cost-effectiveness ratio of £14,026 per QALY gained. This increased to a maximum of £50,000 upon one-way sensitivity analysis of the parameters. At 12 months, the probabilistic sensitivity analysis presented within the submission suggests that the probability that alteplase has a cost-effectiveness ratio greater than £20,000 per QALY gained is approximately 0.7. The guidance issued by NICE in April 2007 as a result of the STA states that alteplase is recommended for the treatment of acute ischaemic stroke only when used by physicians trained and experienced in the management of acute stroke and in centres with the required facilities.

Docetaxel for the adjuvant treatment of early nodepositive breast cancer: a single technology appraisal

This paper presents a summary of the evidence review group (ERG) report into the clinical and cost-effectiveness of docetaxel for the adjuvant treatment of early node-positive breast cancer based upon the manufacturer’s submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The manufacturer’s scope restricts the intervention to docetaxel in combination with doxorubicin and cyclophosphamide (TAC), and the comparator to anthracycline-based chemotherapy. Based on the BCIRG 001 trial, the submitted evidence shows that TAC is associated with superior disease-free and overall survival at 5 years compared with the anthracycline-based regimen FAC. The absolute risk reduction in patients treated with TAC compared with those treated with FAC was 7% for disease-free survival and 6% for overall survival. However, TAC was associated with significantly greater toxicity than FAC. There is also evidence that docetaxel, in an unlicensed sequential regimen FEC100-T, is associated with superior diseasefree and overall survival at 5 years compared with FEC100. An economic model was developed by the manufacturer based on the BCIRG 001 trial. This generated central estimates of the cost per life-year gained and cost per quality-adjusted lifeyear (QALY) gained of TAC compared with FAC of £7900 and £9800 respectively. The manufacturer’s submission predicts a cost-effectiveness of £15,000–£20,000 per QALY gained for TAC compared with E-CMF (epirubicin in sequential therapy with cyclophosphamide, methotrexate, and fluorouracil), and estimates the cost-effectiveness of FEC100-T to be £8200 per QALY compared with FEC100. Taking into account a number of issues identified by the ERG this may generate higher estimates of cost-effectiveness, but these are unlikely to exceed £35,000 per QALY gained. Importantly, FAC is not commonly used in clinical practice in the UK and, therefore, the submitted evidence does not indicate whether TAC is superior to the anthracycline-based regimens that are in common use (FEC or E-CMF). The indirect comparisons presented suggest that the economic case for TAC in comparison to current UK practice may not be proven. The manufacturer’s submission failed to record evidence of three serious adverse events in patients receiving docetaxel with doxorubicin or to mention the concern of the European Medicines Agency regarding TAC’s long-term adverse events. The guidance issued by NICE in June 2006 as a result of the STA states that docetaxel, when given concurrently with doxorubicin and cyclophosphamide (the TAC regimen), is recommended as an option for the adjuvant treatment of women with early nodepositive breast cancer.

How formalin affects the outcome of routine and special stains

The discovery of formaldehyde for preserving tissue structures produced a new dimension in microscopy. Preserving structure and morphology became important; therefore, identifying a proper fixing agent for particular structures, chemical entities, and tissues, also became important. The methods for demonstrating tissue structures evolved and were implemented with careful observation and documentation of the results and outcomes. Formalin was incorporated into many techniques, and provided helpful results in many cases and hindrances in others. The effects of formalin on the outcomes of routine and special staining techniques are reported here.

A systematic review and economic evaluation of alendronate, etidronate, risedronate, raloxifene and teriparatide for the prevention and treatment of postmenopausal osteoporosis

OBJECTIVES

To establish the clinical effectiveness and cost-effectiveness of selective oestrogen receptor modulators, bisphosphonates and parathyroid hormone (subject to licensing) for the prevention and treatment of osteoporosis and the prevention of osteoporotic fractures in postmenopausal women.

DATA SOURCES

Electronic databases.

REVIEW METHODS

Studies that met the review's entry criteria were eligible for inclusion in the meta-analyses provided that they reported fracture incidence in terms of the number of patients suffering fractures. Meta-analysis was carried out using the random-effects model. A model was constructed to estimate the cost-effectiveness of osteoporosis interventions. The model calculated the number of fractures that occurred and provided the costs associated with osteoporotic fractures, and the quality-adjusted life-years (QALYs). In addition, the conditions of breast cancer and coronary heart disease (CHD) were modelled, as some interventions have been shown to affect the risk of these conditions.

RESULTS

Ninety randomised controlled trials (RCTs) met the inclusion criteria. They related to the five interventions (alendronate, etidronate, risedronate, raloxifene and teriparatide) and to five comparators (calcium, calcium plus vitamin D, calcitriol, hormone replacement therapy and exercise), as well as placebo or no treatment. All five interventions have been shown to reduce the risk of vertebral fracture in women with severe osteoporosis with adequate calcium intakes. However, none of these drugs has been demonstrated, by direct comparison, to be significantly more effective than either each other or the other active interventions reviewed in this report. The intervention costs of treating all osteoporotic women, for a period of 5 years, were in the region of pound 900-1500 million for alendronate, etidronate, risedronate and raloxifene. The cost per QALY ratios fell dramatically with age. Assuming the risks of a woman with severe osteoporosis at the threshold of osteoporosis, no treatment had a cost per QALY below pound 35,000 at 50 years of age. At 60 years of age, the cost per QALY of raloxifene was pound 26,000 assuming no impact on hip fractures, and pound 31,000 assuming an adverse effect. However, these results are driven by the effect on breast cancer and the assumptions made regarding this disease state. No other intervention had a cost per QALY below pound 35,000. When analyses were conducted assuming that the fracture risk is doubled at each site, alendronate and risedronate had cost per QALY ratios below pound 30,000 at all ages. For women at the threshold of osteoporosis, without a prior fracture and aged 70 years, the cost per QALY of the three bisphosphonates ranged from pound 34,000 to pound 41,000. Raloxifene had a cost per QALY of pound 23,000, assuming no effect on hip fracture, given assumptions regarding breast cancer. At 80 years of age, the cost per QALY of alendronate and risedronate was below pound 20,000. This was true for etidronate when incorporating observational data, but the value rose to pound 69,000 when only RCT data were used. No other intervention had a cost per QALY below pound 35,000. It was assumed that doubling the risk of fracture for women without a prior fracture would give results similar to patients at the threshold of osteoporosis with a prior fracture.

CONCLUSIONS

Of the five interventions, only raloxifene appeared to reduce the risk of vertebral fracture in postmenopausal women unselected for low bone mineral density (BMD). However, as the full data have not been made public, there is some uncertainty regarding this result. None of the five interventions has been shown to reduce the risk of non-vertebral fracture in women unselected for low BMD. All of the proposed interventions provided gains in QALYs compared with no treatment in women with sufficient calcium and vitamin D intakes. The size of the QALY gain for each intervention was strongly related to the age of the patient. The estimated costs varied widely for the interventions. These net costs were markedly different by age, with some interventions becoming cost-saving at higher age ranges in patients with a prior fracture. Areas for future research include: the evidence base for the efficacy of fracture prevention in the very elderly, reanalysis of raloxifene using a dedicated breast cancer and CHD model, and more trials considering the cost-effectiveness of teriparatide.

A systematic review and economic evaluation of statins for the prevention of coronary events

OBJECTIVES

To evaluate the clinical effectiveness and cost-effectiveness of statins for the primary and secondary prevention of cardiovascular events in adults with, or at risk of, coronary heart disease (CHD).

DATA SOURCES

Electronic databases were searched between November 2003 and April 2004.

REVIEW METHODS

A review was undertaken to identify and evaluate all literature relating to the clinical and cost effectiveness of statins in the primary and secondary prevention of CHD and cardiovascular disease (CVD) in the UK. A Markov model was developed to explore the costs and health outcomes associated with a lifetime of statin treatment using a UK NHS perspective.

RESULTS

Thirty-one randomised studies were identified that compared a statin with placebo or with another statin, and reported clinical outcomes. Meta-analysis of the available data from the placebo-controlled studies indicates that, in patients with, or at risk of, CVD, statin therapy is associated with a reduced relative risk of all cause mortality, cardiovascular mortality, CHD mortality and fatal myocardial infarction (MI), but not of fatal stroke. It is also associated with a reduced relative risk of morbidity [non-fatal stroke, non-fatal MI, transient ischaemic attack (TIA), unstable angina] and of coronary revascularisation. It is hardly possible, on the evidence available from the placebo-controlled trials, to differentiate between the clinical efficacy of atorvastatin, fluvastatin, pravastatin and simvastatin. However, there is some evidence from direct comparisons between statins to suggest that atorvastatin may be more effective than pravastatin in patients with symptomatic CHD. There is limited evidence for the effectiveness of statins in different subgroups. Statins are generally considered to be well tolerated and to have a good safety profile. This view is generally supported both by the evidence of the trials included in this review and by postmarketing surveillance data. Increases in creatine kinase and myopathy have been reported, but rhabdomyolysis and hepatotoxicity are rare. However, some patients may receive lipid-lowering therapy for as long as 50 years, and long-term safety over such a timespan remains unknown. In secondary prevention of CHD, the incremental cost-effectiveness ratios (ICERs) increase with age varying between pound 10,000 and pound 17,000 per quality adjusted life year (QALY) for ages 45 and 85 respectively. Sensitivity analyses show these results are robust. In primary prevention of CHD there is substantial variation in ICERs by age and risk. The average ICERs weighted by risk range from pound 20,000 to pound 27,500 for men and from pound 21,000 to pound 57,000 for women. The results are sensitive to the cost of statins, discount rates and the modelling time frame. In the CVD analyses, which take into account the benefits of statins on reductions in stroke and TIA events, the average ICER weighted by risk level remains below pound 20,000 at CHD risk levels down to 0.5%. Limitations of the analyses include the requirement to extrapolate well beyond the timeframe of the trial period, and to extrapolate effectiveness results from higher risk primary prevention populations to the treatment of populations at much lower risk. Consequently, the results for the lower age bands and lower risks are subject to greater uncertainty and need to be treated with caution.

CONCLUSIONS

There is evidence to suggest that statin therapy is associated with a statistically significant reduction in the risk of primary and secondary cardiovascular events. As the confidence intervals for each outcome in each prevention category overlap, it is not possible to differentiate, in terms of relative risk, between the effectiveness of statins in primary and secondary prevention. However, the absolute risk of CHD death/non-fatal MI is higher, and the number needed to treat to avoid such an event is consequently lower, in secondary than in primary prevention. The generalisability of these results is limited by the exclusion, in some studies, of patients who were hypersensitive to, intolerant of, or known to be unresponsive to, statins, or who were not adequately compliant with study medication during a placebo run-in phase. Consequently, the treatment effect may be reduced when statins are used in an unselected population. The results of the economic modelling show that statin therapy in secondary prevention is likely to be considered cost-effective. In primary prevention, the cost-effectiveness ratios are dependent on the level of CHD risk and age, but the results for the CVD analyses offer support for the more aggressive treatment recommendation issued by recent guidelines in UK. Evidence on clinical endpoints for rosuvastatin is awaited from on-going trials. The potential targeting of statins at low-risk populations is however associated with major uncertainties, particularly the likely uptake and long-term compliance to lifelong medication by asymptomatic younger patients. The targeting, assessment and monitoring of low-risk patients in primary care would be a major resource implication for the NHS. These areas require further research.

Quality assurance and benchmarking: an approach for European dental schools

This document was written by Task Force 3 of DentEd III, which is a European Union funded Thematic Network working under the auspices of the Association for Dental Education in Europe (ADEE). It provides a guide to assist in the harmonisation of Dental Education Quality Assurance (QA) systems across the European Higher Education Area (EHEA). There is reference to the work, thus far, of DentEd, DentEd Evolves, DentEd III and the ADEE as they strive to assist the convergence of standards in dental education; obviously QA and benchmarking has an important part to play in the European HE response to the Bologna Process. Definitions of Quality, Quality Assurance, Quality Management and Quality Improvement are given and put into the context of dental education. The possible process and framework for Quality Assurance are outlined and some basic guidelines/recommendations suggested. It is recognised that Quality Assurance in Dental Schools has to co-exist as part of established Quality Assurance systems within faculties and universities, and that Schools also may have to comply with existing local or national systems. Perhaps of greatest importance are the 14 'requirements' for the Quality Assurance of Dental Education in Europe. These, together with the document and its appendices, were unanimously supported by the ADEE at its General Assembly in 2006. As there must be more than one road to achieve a convergence or harmonisation standard, a number of appendices are made available on the ADEE website. These provide a series of 'toolkits' from which schools can 'pick and choose' to assist them in developing QA systems appropriate to their own environment. Validated contributions and examples continue to be most welcome from all members of the European dental community for inclusion at this website. It is realised that not all schools will be able to achieve all of these requirements immediately, by definition, successful harmonisation is a process that will take time. At the end of the DentEd III project, ADEE will continue to support the progress of all schools in Europe towards these aims.

Control of bleeding in patients with haemophilia A with inhibitors: a systematic review

This paper reports a systematic review of the best available evidence of clinical effectiveness in the treatment of acute bleeding in haemophilia A patients with inhibitors. Because of the lack of randomized controlled trials (RCTs) on this topic, broad inclusion criteria with regard to study design were applied in order to assess the best available evidence for each intervention. Because of the clinical and methodological heterogeneity of the evidence, it was not appropriate to pool data across studies; instead, data were synthesized using tabulation and qualitative narrative assessment. No evidence was found to support the use of high-dose factor VIII (FVIII) in bleeding episodes. However in surgery it was found to be highly successful (100%) for low-titre, low-responding inhibitors although not reliable for high-responding inhibitors. Porcine FVIII (pFVIII) was effective in the control of severe bleeding episodes with high-titre or high-responding inhibitors (100%) and in 60-90% of surgical procedures. Activated prothrombin complex concentrates (APCCs) appear to be more effective than prothrombin complex concentrates (PCCs) in the control of mild to severe bleeding episodes. There was no good evidence for the use of PCCs in surgery. APCCs controlled bleeding in approximately 90% of surgical episodes. Recombinant factor VIIa (rFVIIa) controlled 70-100% of mild to severe bleeding episodes with high-responding inhibitors, and achieved better results when used early. It was effective in 60-100% of surgical episodes. Doses varied from study to study, and side-effects from mild to infrequent but serious adverse events were reported. The quality of the evidence is variable. Limited evidence relating to other treatment options is also included in the review.

Economic modelling of different treatment strategies for haemophilia A with high-responding inhibitors

This paper reports a systematic review of the cost-effectiveness of treatment options in patients with haemophilia A with inhibitors. As very little relevant published evidence was identified, an economic modelling exercise was undertaken to calculate the cost-effectiveness of different strategies in the treatment of high-responding haemophilia A patients with inhibitors. A decision analysis approach was used to model the expected lifetime clinical outcomes and costs of the more common regimens currently used in UK in treating severe haemophiliacs with inhibitors. The model attempts to reflect the outcomes of clinical events, costs and life expectancy for each different treatment regimen for haemophilic boys with inhibitors who are high responders (defined as inhibitor level >/=10 BU) throughout their life. The basic model structure is centred on a Markov decision process, which was used to simulate, at quarter-yearly intervals, the movement through discrete health states and their complications. The model allows a comparison of cost-effectiveness between three immune tolerance induction (ITI) regimens (Bonn, Mälmo and Low-Dose protocols) and against a relevant 'on-demand' (OD) regimen. It also shows the cost-effectiveness of different OD regimens using different bypassing agents. The results of the economic modelling indicate that treating haemophilia A patients who have high-responding inhibitors OD with recombinant activated factor VII is cost-effective compared to treatment with activated prothrombin complex concentrates. However, when OD treatment regimens are compared with the three ITI protocols, the Malmö ITI protocol is the preferred treatment strategy, generating more quality adjusted life-years (QALYs) and less cost than either an OD regimen or the Bonn or Low-Dose ITI protocols.

Phospholipase C isoforms in mammalian spermatozoa: potential components of the sperm factor that causes Ca2+ release in eggs

Injection of a soluble protein factor from mammalian spermatozoa triggers Ca2+ oscillations in mammalian eggs similar to those seen at fertilization. This sperm factor also generates inositol 1,4,5-trisphosphate and causes Ca2+ release in sea urchin egg homogenates and frog eggs. Recent studies have indicated that the sperm factor may be an inositol-specific phospholipase C (PLC) activity. This study investigated whether any of the commonly known PLC isoforms are components of the sperm factor. PLCbeta, PLCgamma and PLCdelta isoforms were shown to be present in boar sperm extracts. However, upon column fractionation of sperm extracts, none of the PLC isoforms detected correlated with the ability to cause Ca2+ release in eggs. In addition to our previous work on recombinant PLCs, it was also shown that PLCdelta3, PLCdelta4 and its splice variant PLCdelta4 Alt1 fail to cause Ca2+ release. The recently discovered 255 kDa PLCepsilon isoform also appears unlikely to be a component of the sperm factor, as fractionation of sperm extracts on a gel filtration column demonstrated that the peak of Ca2+-releasing activity was associated with fractions of 30-70 kDa. These findings indicate that the sperm factor that triggers Ca2+ release in eggs does not appear to have a known PLC isoform as one of its components.

A systematic review of the clinical effectiveness of pioglitazone in the treatment of type 2 diabetes mellitus

BACKGROUND

Pioglitazone is a member of a recently developed class of glucose-lowering agents, the thiazolidinediones, used in the treatment of type 2 diabetes mellitus. In the United States, it is approved for use both as monotherapy and in combination with metformin, a sulfonylurea, or insulin; in Europe, it is approved for use in combination with metformin or a sulfonylurea but not insulin.

OBJECTIVE

This article presents a systematic review of the published literature on the effectiveness of pioglitazone in the treatment of type 2 diabetes, both as monotherapy and in combination with other antidiabetic agents.

METHODS

The peer-reviewed English- and foreign-language literature was searched using MEDLINE, PubMED, EMBASE, Science Citation Index, the Cochrane Database of Systematic Reviews, the Cochrane Controlled Trials Register, the UK National Health Service Centre for Reviews and Dissemination databases, and the Office of Health Economics Health Economic Evaluations Database. Searches were not limited to specific publication types, study designs, dates, or languages. The latest search was performed in March 2001. For a trial to be included in the review, at least 1 outcome measure had to involve the effects of pioglitazone on glycemic control or cardiovascular risk factors, or its side effects. Because of the heterogeneity of studies, no formal meta-analysis was performed.

RESULTS

Eleven studies met the inclusion criteria, 6 involving pioglitazone monotherapy and 5 involving combination therapy. Full reports were available for only 6 of the 11 studies. No studies directly compared pioglitazone with other antidiabetic drugs. Both as monotherapy and in combination therapy, pioglitazone produced decreases in blood glucose levels (up to 95 mg/dL) and glycosylated hemoglobin (up to 2.6%). At doses of > or = 30 mg/d, pioglitazone was associated with reductions in triglyceride levels (-30-70 mg/dL) and increases in high-density lipoprotein cholesterol (HDL-C) levels (-4-5 mg/dL). Pioglitazone treatment was associated with significant weight gain (up to 4 kg over 16 weeks). Adverse effects included mild edema (in up to 11.7% of patients) and a clinically nonsignificant decrease in hemoglobin concentrations. Abnormal results on liver function testing were no more common in treated patients than in control groups.

CONCLUSIONS

Pioglitazone has been shown to reduce blood glucose levels in patients with type 2 diabetes. Although the observed decreases in triglyceride levels and increases in HDL-C levels could be expected to lead to a reduction in cardiovascular risk, the effects of weight gain may counteract this benefit. The evidence suggests that the preferred role for pioglitazone may be as an adjunct to metformin or a sulfonylurea in patients whose condition is not well controlled with monotherapy and for whom a metformin-sulfonylurea combination is contraindicated. There is a need for large-scale, long-term studies comparing the effectiveness of combination therapy that includes pioglitazone with that of other combinations of antidiabetic drugs.

The Balanced Scorecard: a strategic management system for multi-sector collaboration and strategy implementation

This article illustrates the application of the Balanced Scorecard, a method more commonly associated with the business world, to a nonprofit multisector National Women's Health Quality Initiative (NWHQI). The article delineates the following multiple uses of the Balanced Scorecard for the NWHQI effort: Set NWHQI strategy and structure. Provide the framework and principles to implement NWHQI's strategy. Develop a measurement system to assess the progress and success of NWHQI's strategy. Serve as a collaboration mechanism for multisector stakeholders. Advance women's health knowledge base. This article concludes by sharing key insights regarding the utility of the Balanced Scorecard to promote the success of this nationwide women's health quality initiative.

Implementation and outcomes of a balanced scorecard model in women's services in an academic health care institution

In the current, chaotic health care climate an important success determinant for health care administrators and clinicians is the support of timely, collaborative decisions for delivery of patient care. The purpose of this article is to describe implementation and outcomes of the application of the Balanced Scorecard (BSC) model, a strategic management system, for a Women's Services Clinical Business Unit (CBU) in an academic health care institution, a complex adaptive system. Emphasis is focused on crucial process and outcome indicators that demonstrate how the work of all team members makes a difference at the point of clinical services across the continuum. Finally, implications for leadership development are revealed from the principles underlying complexity science.

Induction of abnormal Chlamydia trachomatis by exposure to interferon-gamma or amino acid deprivation and comparative antigenic analysis

Abnormal forms of Chlamydia trachomatis have been induced in vitro by a variety of methods including nutrient deprivation, addition of cytokines and addition of antibiotics. These forms have been shown to have altered morphology and infectivity and have been implicated in persistent infections in vivo although there is little direct evidence for their presence. Likely sites for abnormal forms in vivo are the genital tract and the synovial tissue of reactive arthritis patients, and T cells isolated from the synovial tissue have been shown to be specific for chlamydial antigens, in particular the Hsp60. Since T cell specificity is so important in reactive arthritis disease the antigenic composition of abnormal forms induced by Interferon-gamma and amino acid deprivation has been examined by western blotting in two strains of C. trachomatis belonging to different biovars. The degree of abnormality of the organisms was found to increase as the treatments became more severe. No simple patterns of antigenic changes were found and differences in the antigenic composition were seen in abnormal forms induced by the different treatments and also in the different strains.

The implications of contact with the mentor for preregistration nursing and midwifery students

AIM OF THE PAPER

To examine the extent to which preregistration nursing and midwifery students have contact with their named mentor, and the implications of this.

BACKGROUND/RATIONALE

Mentorship has an important part to play in enabling preregistration nursing and midwifery students to gain the maximum benefit from clinical placements. Previous research has indicated that the benefits of mentorship to learners are related to the number of occasions on which the student and mentor work together.

DESIGN/METHODS

A research project commissioned by the Sheffield and North Trent College of Nursing and Midwifery (now the University of Sheffield School of Nursing and Midwifery) provided an opportunity to examine the extent to which their named mentors were available to Project 2000 students, and the implications of this. Students and their named mentors were asked to keep an activity diary for 1 week. The main objective was to collect activity data to inform an analysis of the costs and benefits of clinical placements to service providers. This cost-benefit study has been published elsewhere. However, the data also cast light on the extent to which mentors were available to students, and the implications of this, and it is these findings which are presented here.

RESULTS/FINDINGS

Students frequently worked shifts without their named mentors even though unrostered students often worked weekends, evening and night shifts in order to maximize time spent with their mentors. In the mentor's absence, other members of staff covered for some of their activities (in particular, direct and indirect supervision of students). However, students whose named mentors were absent spent significantly less time than other students working with a qualified member of staff as a partner in giving care.

CONCLUSIONS

It is suggested that the extent to which named mentors are unavailable to Project 2000 students may be detrimental to the education and professional development of those students.

An evaluation of the quality of orthodontic attachment offered by single- and double-mesh bracket bases using the finite element method of stress analysis

The objective of this study was to evaluate the influence of bracket base mesh geometry on the stresses generated in the bracket-cement-tooth continuum by a shear/peel load case. A validated three-dimensional finite element model of the bracket-cement-tooth system was constructed consisting of 15,324 nodes and 2971 finite elements. Cement geometric and physical properties were held constant and bracket base geometry was varied, representing a variety of single-mesh configurations and 1 double-mesh design. For the single-mesh designs, increasing wire diameter (100-400 microm) resulted in a decrease in enamel and cement stresses. Increases in wire mesh spacing (200-750 microm) increased the major principal stress recorded in the enamel and adhesive at all wire diameters. Within the bracket, the major principal stress increased significantly at wire spacing above 400-500 microm. However, within the impregnated wire mesh (IWM), the major principal stress decreased as wire space increased. When the double-mesh bracket base was considered, the combined mesh layers resulted in a decrease in the stresses recorded in the most superficial (coarse) mesh layer and an increase in the stresses recorded in the deepest (fine mesh) layer when compared with the single-layer designs in isolation. Modification of single-mesh spacing and wire diameter influences the magnitude and distribution of stresses within the bracket-cement-tooth continuum. The use of a double-mesh design results in a reduction in the stresses recorded in the most superficial mesh. Mesh design influenced stress distribution in this study, primarily by determining the flexibility of the bracket base.

A validated finite element method study of orthodontic tooth movement in the human subject

The aim of the study was to develop a 3D computer model of the movement of a maxillary incisor tooth when subjected to an orthodontic load. A novel method was to be developed to directly and accurately measure orthodontic tooth movement in a group of human volunteers. This was to be used to validate the finite element-based computer model. The design took the form of a prospective experiment at a laboratory at the University of Wales in 1996/7. A laser apparatus was used to sample tooth movement every 0.01 seconds over a 1-minute cycle for 10 healthy volunteers, whilst a constant 0.39 N load was applied. This process was repeated on eight separate occasions and the most consistent five readings taken for each subject. Data were used to calculate the physical properties of the periodontal ligament (PDL). The data gleaned by this method were used to validate the 3D FEM model. This was formed of 15,000 four-noded tetrahedral elements. Tooth displacements ranged from 0.012 to 0.133 mm. An appropriate elastic modulus of 1 N/mm(2) and Poisson's Ratio of 0.45 was derived for the PDL. Strain analysis, using the model, suggested that a maximum PDL strain of 4.77 x 10(-3) was recorded at the alveolar crest, while the largest apical strain recorded was 1.55 x 10(-3). The maximum strains recorded in the surrounding alveolar bone were 35 times less than for the PDL. A novel method for direct measurement of PDL physical properties in the human subject has been developed. The validated FEM model lends further evidence that the PDL is the main mediator of orthodontic tooth movement.

An evaluation of the influence of orthodontic adhesive on the stresses generated in a bonded bracket finite element model

The objective of this study was to evaluate the stresses generated in the bracket-cement-tooth continuum by a tensile load case when the physical and geometric properties of cement are varied. A 2-stage approach was used. In the first stage, a validated 3-dimensional finite element model of the bracket-cement-tooth system was constructed that consisted of 15,324 nodes and 2971 finite elements. Bracket base geometry was held constant; the physical properties (elastic modulus; Poisson's ratio) and geometry (lute thickness) of the cement varied. A simplified 2-dimensional model was then developed to investigate the localized effects of the cement lute thickness and the shape of the lute periphery on the stress distribution in the system. Small increases in stress were recorded under load within the cement as the rigidity of the cement increased. Similarly, Poisson's ratio values above 0.4 appeared to have a small influence on the major principal stresses in the impregnated wire mesh layer when a tensile force was applied. Variation in lute thickness was shown to have an influence on the distribution of major principal stresses within the cement lute. Increased stresses were recorded at the lute periphery as the lute dimensions increased. The morphologic features of the lute periphery also appeared to have had a significant effect on the performance of an orthodontic adhesive. Acute cement-enamel angles resulted in an increased chance of singularity development and attachment failure. The physical properties and thickness of the cement lute and the shape of the cement lute periphery contribute to the stress distribution within the bracket-cement-tooth continuum and, therefore, the quality of orthodontic attachment provided.

Initial experiences with telerehabilitation and contingency management programs for the prevention and management of pressure ulceration in patients with spinal cord injuries

Two alternative treatment methods for preventive interventions for pressure ulcers, tele-rehabilitation and contingency management, are discussed. Telerehabilitation uses a videophone that transmits both audio and still images over a telephone line. Using this technology, the WOC nurse can interview a patient who cannot be present at a clinic because of physical condition or distance. Telerehabilitation allows the nurse to assess a patient's pressure ulcer, consult with appropriate caregivers, and make recommendations for treatment. Contingency management procedures are designed for patients with high rates of noncompliance in skin care. The patients are seen as outpatients and are compensated systematically for appropriate skin care (ie, the lack of pressure ulcers). Examples of each of these patient interventions is described, discussed, and contrasted.

The influence of bracket base design on the strength of the bracket-cement interface

The objectives of the study were to isolate the bracket-cement interface, and to determine the influence of bracket base morphology and orthodontic bonding agent chosen on strength of adhesion. The bracket bases evaluated included 60, 80, and 100 single mesh bases, a double mesh base, and the Dynalock, and Mini Twin bases. The strength of interface provided by each of these bases with Concise, Transbond, Right On, and non-encapsulated Fuji Ortho LC cements, was measured in tension and recorded in Mega Pascals. The single-mesh bases performed well with either Concise or Right On (11*88-22*72 MPa) and, other than the 80-mesh bracket, relatively poorly with Transbond (2*18-5*15 MPa). With Fuji Ortho LC, the single mesh bases performed well (6*05-12*19 MPa). The double mesh base performed well with Right On (13*75 MPa), and reasonably well with Concise, Transbond, and Fuji Ortho LC (6*00-9*20 MPa). The Dynalock and Mini Twin Bases performed fairly well with all cements (8*87-17*16 MPa). It was concluded that the orthodontic bonding agent selected would appear to largely determine the bond strength achieved with a particular bracket base design. A definite trend was difficult to identify in this study, and it appeared that certain combinations of bracket base and bonding agent performed optimally. Particular base designs may allow improved adhesive penetration or improved penetration of curing light. Alternatively, the dimension and distribution of resin/cement tags prescribed by one base could promote a stress distribution that is better resisted by a particular adhesive.