The structural basis for the functional comparability of factor VIII and the long-acting variant recombinant factor VIII Fc fusion protein.

Essentials Recombinant factor VIII (rFVIII) Fc fusion protein has a 1.5-fold longer half-life than rFVIII. Five orthogonal methods were used to characterize the structure of rFVIIIFc compared to rFVIII. The C-terminal Fc fusion does not perturb the structure of FVIII in rFVIIIFc. The FVIII and Fc components of rFVIIIFc are flexibly tethered and functionally independent. SUMMARY: Background Fusion of the human IgG1 Fc domain to the C-terminal C2 domain of B-domain-deleted (BDD) factor VIII (FVIII) results in the recombinant FVIII Fc (rFVIIIFc) fusion protein, which has a 1.5-fold longer half-life in humans. Objective To assess the structural properties of rFVIIIFc by comparing its constituent FVIII and Fc elements with their respective isolated components, and evaluating their structural independence within rFVIIIFc. Methods rFVIIIFc and its isolated FVIII and Fc components were compared by the use of hydrogen-deuterium exchange mass spectrometry (HDX-MS). The structure of rFVIIIFc was also evaluated by the use of X-ray crystallography, small-angle X-ray scattering (SAXS), and electron microscopy (EM). The degree of steric interference by the appended Fc domain was assessed by EM and surface plasmon resonance (SPR). Results HDX-MS analysis of rFVIIIFc revealed that fusion caused no structural perturbations in FVIII or Fc. The rFVIIIFc crystal structure showed that the FVIII component is indistinguishable from published BDD FVIII structures. The Fc domain was not observed, indicating high mobility. SAXS analysis was consistent with an ensemble of rigid-body models in which the Fc domain exists in a largely extended orientation relative to FVIII. Binding of Fab fragments of anti-C2 domain antibodies to BDD FVIII was visualized by EM, and the affinities of the corresponding intact antibodies for BDD FVIII and rFVIIIFc were comparable by SPR analysis. Conclusions The FVIII and Fc components of rFVIIIFc are structurally indistinguishable from their isolated constituents, and show a high degree of structural independence, consistent with the functional comparability of rFVIIIFc and unmodified FVIII.

Lysophosphatidic acid provides a missing link between osteoarthritis and joint neuropathic pain.

OBJECTIVE: Emerging evidence suggests that osteoarthritis (OA) has a neuropathic component; however, the identity of the molecules responsible for this peripheral neuropathy is unknown. The aim of this study was to determine the contribution of the bioactive lipid lysophosphatidic acid (LPA) to joint neuropathy and pain. DESIGN: Male Lewis rats received an intra-articular injection of 50 µg of LPA into the knee and allowed to recover for up to 21 days. Saphenous nerve myelination was assessed by g-ratio calculation from electron micrographs and afferent nerve damage visualised by activation transcription factor-3 (ATF-3) expression. Nerve conduction velocity was measured electrophysiologically and joint pain was determined by hindlimb incapacitance. The effect of the LPA antagonist Ki-16425 was also evaluated. Experiments were repeated in the sodium monoiodoacetate (MIA) model of OA. RESULTS: LPA caused joint nerve demyelination which resulted in a drop in nerve conduction velocity. Sensory neurones were ATF-3 positive and animals exhibited joint pain and knee joint damage. MIA-treated rats also showed signs of demyelination and joint neuropathy with concomitant pain. Nerve damage and pain could be ameliorated by Ki-16425 pre-treatment. CONCLUSION: Intra-articular injection of LPA caused knee joint neuropathy, joint damage and pain. Pharmacological blockade of LPA receptors inhibited joint nerve damage and hindlimb incapacitance. Thus, LPA is a candidate molecule for the development of OA nerve damage and the origin of joint neuropathic pain.

Identification and pharmacological characterization of a novel inhibitor of autotaxin in rodent models of joint pain.

OBJECTIVE: Autotaxin is a secreted lysophospholipase that mediates the conversion of lysophosphatidyl choline (LPC) to lysophosphatidic acid (LPA), a bioactive lipid mediator. Autotaxin levels in plasma and synovial fluid correlate with disease severity in patients with knee osteoarthritis (OA). The goal of this study was to develop and characterize a novel small molecule inhibitor of autotaxin to inhibit LPA production in vivo and determine its efficacy in animal models of musculoskeletal pain. DESIGN: Compound libraries were screened using an LPC coupled enzyme assay that measures the amount of choline released from LPC by the action of autotaxin. Hits from this assay were tested in a plasma assay to assess inhibition of endogenous plasma autotaxin and subsequently tested for their ability to lower plasma LPA levels upon oral dosing of rats. The best compounds were then tested in animal models of musculoskeletal pain. RESULTS: Compound screening led to the identification of compounds with nanomolar potency for inhibition of autotaxin activity. Studies in rats demonstrated a good correlation between compound exposure levels and a decrease in LPA levels in plasma. The leading molecule (compound-1) resulted in a dose dependent decrease in joint pain in the mono-sodium iodoacetate (MIA) and meniscal tear models and a decrease in bone fracture pain in the osteotomy model in rats. CONCLUSION: We have identified and characterized a novel small molecule inhibitor of autotaxin and demonstrated its efficacy in animal models of musculoskeletal pain. The inhibitor has the potential to serve as an analgesic for human OA and bone fracture.

Development of a novel antibody to calcitonin gene-related peptide for the treatment of osteoarthritis-related pain.

OBJECTIVE: Investigate a role for calcitonin gene-related peptide (CGRP) in osteoarthritis (OA)-related pain. DESIGN: Neutralizing antibodies to CGRP were generated de novo. One of these antibodies, LY2951742, was characterized in vitro and tested in pre-clinical in vivo models of OA pain. RESULTS: LY2951742 exhibited high affinity to both human and rat CGRP (KD of 31 and 246 pM, respectively). The antibody neutralized CGRP-mediated induction of cAMP in SK-N-MC cells in vitro and capsaicin-induced dermal blood flow in the rat. Neutralization of CGRP significantly reduced pain behavior as measured by weight bearing differential in the rat monoiodoacetate model of OA pain in a dose-dependent manner. Moreover, pain reduction with neutralization of CGRP occurred independently of prostaglandins, since LY2951742 and NSAIDs worked additively in the NSAID-responsive version of the model and CGRP neutralization remained effective in the NSAID non-responsive version of the model. Neutralization of CGRP also provided dose-dependent and prolonged (>60 days) pain reduction in the rat meniscal tear model of OA after only a single injection of LY2951742. CONCLUSIONS: LY2951742 is a high affinity, neutralizing antibody to CGRP. Neutralization of CGRP is efficacious in several OA pain models and works independently of NSAID mechanisms of action. LY2951742 holds promise for the treatment of pain in OA patients.

The OARSI histopathology initiative - recommendations for histological assessments of osteoarthritis in the mouse.

AIM: To describe a histologic scoring system for murine osteoarthritis (OA) that can be applied universally to instability, enzymatic, transgenic and spontaneous OA models. METHODS: Scientists with expertise in assessing murine OA histopathology reviewed the merits and drawbacks of methods described in the literature. A semi-quantitative scoring system that could reasonably be employed in any basic cartilage histology laboratory was proposed. This scoring system was applied to a set of 10 images of the medial tibial plateau and femoral condyle to yield 20 scores. These images were scored twice by four experienced scorers (CL, SG, MC, TA), with a minimum time interval of 1 week between scores to obtain intra-observer variability. An additional three novice scorers (CR, CL and MM) with no previous experience evaluated the images to determine the ease of use and reproducibility across laboratories. RESULTS: The semi-quantitative scoring system was relatively easy to apply for both experienced and novice scorers and the results had low inter- and intra-scorer variability. The variation in scores across both the experienced and novice scorers was low for both tibia and femur, with the tibia always having greater consistency. CONCLUSIONS: The semi-quantitative scoring system recommended here is simple to apply and required no specialized equipment. Scoring of the tibial plateaus was highly reproducible and more consistent than that of the femur due to the much thinner femoral cartilage. This scoring system may be a useful tool for both new and experienced scorers to sensitively evaluate models and OA mechanisms, and also provide a common paradigm for comparative evaluation across the many groups performing these analyses.

A short-term pharmacodynamic model for monitoring aggrecanase activity: injection of monosodium iodoacetate (MIA) in rats and assessment of aggrecan neoepitope release in synovial fluid using novel ELISAs.

OBJECTIVE: To develop a short-term in vivo model in rats, with an enzyme-linked immunosorbent assay (ELISA) readout for specific aggrecanase-cleaved aggrecan fragments, to facilitate testing of aggrecanase inhibitors. METHODS: Monosodium iodoacetate (MIA), a metabolic inhibitor, was injected into the right knee joint of male Lewis rats and the release of aggrecanase-cleaved fragments of aggrecan containing the NITEGE or ARGN neoepitope was measured in the synovial fluid at 7 days post MIA injection using novel ELISAs. The ELISAs utilize a commercial antibody directed against the hyaluronic-acid binding region (HABR) of aggrecan, in combination with either an alpha-NITEGE antibody (NITEGE ELISA) or an alpha-ARGS/BC3 antibody (ARGS ELISA), to detect aggrecanase-cleavage of aggrecan within the interglobular domain (IGD). Aggrecan fragments present in in vitro digests, in cytokine-treated cartilage explant culture supernatants and in rat synovial fluid lavage samples were detected and quantified using the two ELISAs. Small molecule inhibitors of aggrecanase activity were dosed orally on days 3-7 to determine their ability to inhibit MIA-induced generation of the NITEGE and ARGN neoepitopes measured in the rat synovial fluid. RESULTS: The NITEGE assay was shown to specifically detect the N-terminal fragment of aggrecan comprising the G1 domain and the NITEGE neoepitope sequence. This assay can readily measure aggrecanase-cleaved bovine, human and rat aggrecan without the need for deglycosylation. The ARGS assay specifically detects C-terminal fragments of aggrecan comprising the ARGS/ARGN neoepitope and the G2 domain. Keratan sulfate (KS) residues of aggrecan interfere with this ELISA, and hence this assay works well with native rat articular cartilage aggrecan (that lacks KS residues) and with deglycosylated bovine and human aggrecan. Injection of MIA into the rat knee joints resulted in a time-dependent increase in the release of aggrecanase-cleaved aggrecan fragments into the synovial fluid and treatment with an aggrecanase inhibitor resulted in a dose-dependent inhibition of the generation of these neoepitopes. CONCLUSIONS: We have established a short-term in vivo model in rats that involves measurement of synovial fluid biomarkers that are dependent on aggrecanase activity in the joint. The short duration of the model combined with the mechanistic biomarker readout makes it very useful for the initial in vivo screening of aggrecanase inhibitors prior to testing them in time and resource-intensive disease models of osteoarthritis (OA).

Analysis of early changes in the articular cartilage transcriptisome in the rat meniscal tear model of osteoarthritis: pathway comparisons with the rat anterior cruciate transection model and with human osteoarthritic cartilage.

OBJECTIVE: The purpose of this study was to use microarray technology to: (1) understand the early molecular events underlying the damage of articular cartilage initiated by this surgical procedure, and (2) determine whether these changes mimic those that are occurring in human osteoarthritic (OA) cartilage. DESIGN: Cartilage was harvested from both medial and lateral sides of the tibial plateaus and femoral condyles of both meniscal tear (MT) and sham surgery groups on days 3, 7 and 21 post-surgery. mRNA prepared from these rat cartilage samples was used for microarray analysis. RESULTS: Statistical analysis identified 475 genes that were differentially expressed between the sham and MT groups, at one or more of the time points that were analyzed. By integrating these genes with OA-related genes reported previously in a rat OA model and in human OA array studies, we identified 20 commonly changed genes. Six out of these 20 genes (Col5A1, Col6A2, INHBA, LTBP2, NBL1 and SERPINA1) were differentially expressed in two animal models and in human OA. Pathway analysis identified some key features of OA pathology, namely cartilage extracellular matrix remodeling, angiogenesis, and chondrocyte cell death that were recapitulated in the animal models. The rat models suggested increased inflammation and cholesterol metabolic pathways may play important role in early cartilage degeneration. CONCLUSION: We identified a large number of differentially expressed genes in the articular cartilage of the MT model. While there was lack of overall identity in cartilage gene expression between the rat models and human OA, several key biological processes were recapitulated in the rat MT OA model.

The economics of drug discovery and the ultimate valuation of pharmacotherapies in the marketplace.

Although it is commonly believed that the innovation of new medicines is of paramount importance for improving the health and quality of life of patients, there is also a keen recognition regarding upward-spiraling costs of innovation, drug discovery, and drug development against a backdrop of dwindling successes in research and development (R&D) efforts. We propose a new model of valuation of pharmacotherapies that attempts to secure an adequate return on investment in innovation by ensuring optimal pricing and reimbursement.

The role of adenosine in chondrocyte death in murine osteoarthritis and in a murine chondrocyte cell line.

OBJECTIVE: To investigate the role of adenosine in chondrocyte death in murine osteoarthritis (OA). METHODS: 5'-Nucleotidase (5'NT) generates adenosine. Enzyme activity was measured histochemically in normal murine and osteoarthritic STR/ort strain tibial cartilage. Adenosine-mediated cell death was investigated in MC615 chondrocyte cultures. Adenosine receptors (ARs) were assessed by reverse transcriptase polymerase chain reaction (RT-PCR). Cellular uptake of [(3)H] adenosine was measured with or without the inhibitor, nitrobenzylthioinosine (NBTI). Cell death was assessed by cell counting and DNA laddering following selective receptor stimulation, or after modulating adenosine metabolism with adenosine deaminase (ADA) or adenosine kinase (AK) inhibitors [erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) and Iodotubericidin (Itub)], or with homocysteine (HC). Markers of apoptosis were assessed by Western blotting. Cell studies were validated by incubating normal murine knee joints in a medium containing adenosine and metabolic inhibitors. Apoptotic chondrocytes were identified with the TUNEL reaction. RESULTS: 5'NT activity in STR/ort tibial cartilage increased with development of OA, especially close to OA lesions. Adenosine induced MC615 cell death in the presence of ADA inhibition (100 microM EHNA), or 1mM HC, or both. Adenosine uptake, mediated by NBTI-sensitive adenosine transporters, was required for cell death. ARs were expressed (A2b>A2a>A1) but were not involved in mediating cell death. Cell death involved the activation of caspase-3 and DNA fragmentation and was prevented by inhibiting caspase activity. However, neither caspase-8 nor caspase-9 was detected. Adenosine+EHNA induced chondrocyte apoptosis in normal murine knee joints. CONCLUSION: Increased adenosine production may induce chondrocyte apoptosis and play a role in OA in STR/ort mice.

Chondrocyte death during murine osteoarthritis.

OBJECTIVE: To determine whether chondrocyte apoptosis occurs during the progression of osteoarthritis (OA) in the STR/ort mouse model of OA. METHODS: Serial cryostat sections were cut (10 microns) through the knee joint of young and old male STR/ort mice and graded for the severity of OA lesions. Age- and sex-matched CBA mice were used as controls. Apoptotic chondrocytes were detected using the TUNEL assay. Ultrastructural changes were examined using electron microscopy (EM). Expression of biochemical markers associated with apoptosis (bax, bcl-2 and caspases-3, -8 & -9) was investigated using immunohistochemistry. RESULTS: TUNEL assays on histological sections of STR/ort knee joints showed that the number of TUNEL-positive chondrocytes in the tibial medial articular cartilage correlated with the severity of the OA damage. These cells were located close to the lesional area. Only very occasional TUNEL positive chondrocytes were detected in either morphologically normal STR/ort cartilage or in control CBA cartilage. Ultrastructural analysis of chondrocytes neighboring focal osteoarthritic lesions in STR/ort tibial cartilage revealed an abundance of abnormal cells exhibiting numerous morphological changes. These resembled, but in some cases differed, from changes reported in classical apoptosis. The changes include abnormal distribution of chromatin, cell shrinkage, membrane blebbing and deposition of cell remnants (apoptotic bodies) in the lacuna space. Despite the TUNEL and EM changes, immunohistochemistry failed to detect any changes in the ratio of bax to bcl-2 in tibial chondrocytes of STR/ort mice. Both bcl-2 and bax levels decreased with age in morphologically normal STR/ort and control CBA cartilage. None of the caspases tested for was detected in tibial chondrocytes of either strain. CONCLUSION: Chondrocyte cell death is correlated with the progression of OA in STR/ort mice and has many of the morphological characteristics of classical apoptosis. Absence of changes in bax to bcl-2 ratio in STR/ort chondrocytes indicate that the mitochondrial pathway of apoptosis is unlikely to be involved. Failure to detect caspases could be due to low levels of enzyme expression, expression within a very brief time period, or to a caspase-independent mechanism of cell death.

Distribution of Endo180 receptor and ligand in developing articular cartilage.

OBJECTIVE: To investigate the expression of a novel member of the mannose receptor family, Endo180 (also known as uPARAP), and the distribution of Endo180 ligand(s) in the articular cartilage and growth plate of normal CBA mice and STR/ort mice, a well characterized model of spontaneous osteoarthritis. DESIGN: A polyclonal anti-Endo180 antibody was used to determine receptor expression. The Endo180 extracellular domain fused to a human immunoglobulin Fc tail was used to detect ligand. RESULTS: Endo180 receptor was strongly expressed in chondrocytes both in vitro and throughout the articular cartilage of young CBA and STR/ort mice. Expression decreased in older animals. In STR/ort mice with osteoarthritic lesions, no upregulation of Endo180 was detected. In the developing growth plate, Endo180 was expressed strongly by the proliferating chondrocytes. In contrast, Endo180 ligand was detected most strongly in hypertrophic zone of the growth plate and only at low levels in articular cartilage. In cultured chondrocytes, Endo180 was localized on the cell surface and in intracellular vesicles. CONCLUSION: Constitutively recycling endocytic receptors function to internalize ligand from the extracellular milieu and the ability of Endo180 to bind both glycosylated ligands and collagens suggests a role in extracellular matrix remodeling. Expression of Endo180 in articular cartilage chondrocytes of young, but not old, mice and the reciprocal expression of Endo180 and its ligands in the growth plate suggest that this receptor is involved in cartilage development but not in cartilage homeostasis. In addition, our data indicates that Endo180 does not appear to play a role in the development or progression of murine osteoarthritis.

Metalloproteinase and tissue inhibitor of metalloproteinase expression in the murine STR/ort model of osteoarthritis.

OBJECTIVE: To study the temporal expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in the STR/ort mouse model of osteoarthritis, using in situ hybridization with oligonucleotide probes and specific antisera for each protein. METHODS: In situ hybridization and immunolocalization experiments were performed on serial cryosections of knee joints from STR/ort and control CBA mice. The mRNA was localized using digoxygenin-labeled probes. RESULTS: MMP2, MMP3, MMP7, MMP9, MMP13, MT1-MMP and TIMP2 mRNA was detected in the tibial articular chondrocytes of STR/ort mice at all ages (12, 18, 24, 30 and 35 weeks). Levels were always higher than in age-matched CBA mice. Neither MMP8 nor TIMP1 mRNA was detected in murine cartilage. The location and distribution of each of the MMP mRNA transcripts varied within the tibial plateau. Immunolocalization consistently detected MMP3 and MT1-MMP in articular cartilage and MMP13 in calcified cartilage. Other proteases and their inhibitors were not detected in either of these cartilages but MMP2 and MMP9 were immunolocalized in bone marrow cells and growth cartilage respectively. CONCLUSION: Expression of all the detected MMPs and TIMP-2 is up-regulated in STR/ort mice at the mRNA level. However, failure to detect protein expression for MMPs 2, 7, 9, 13 and TIMPs 1 and 2 in murine chondrocytes by immunohistochemistry indicates that the changes in mRNA levels in STR/ort mice must be interpreted with caution.

Comparison of collagenase-cleaved articular cartilage collagen in mice in the naturally occurring STR/ort model of osteoarthritis and in collagen-induced arthritis.

OBJECTIVE: The STR/ort mouse develops a naturally occurring osteoarthritis of the femorotibial joint that provides a model with which to establish the time course of biochemical changes taking place in articular cartilage in the disease. Our objective was to define the onset, location and progression of type II collagen cleavage by collagenase in the tibial cartilage of the STR/ort mouse. For comparison, cartilage collagen cleavage was also studied in collagen-induced arthritis in DBA mice. DESIGN: STR and control CBA mice aged 6-45 weeks were examined. DBA/1 mice were studied 2 and 3 weeks after initiating collagen-induced arthritis. Collagen cleavage was detected by immunolocalization using the antibody COL2-3/4Cshort which recognizes a carboxy terminal neoepitope created by collagenase cleavage of type I and II collagens. RESULTS: No COL 2-3/4Cshort immunostaining was observed in the intact cartilage of healthy young or old mice. The earliest detectable collagen degradation occurred at the cartilage surface coincident with the appearance of surface roughening. As fibrillations developed, further collagen degradation was evident around the edge of the lesion and in adjacent extracellular matrix. In contrast, staining was observed throughout the cartilage matrix in type II collagen-induced arthritis prior to the development of histopathological lesions. CONCLUSION: No evidence was found for collagen cleavage in intact/pre-lesional cartilage from STR/ort mice. Local collagen cleavage was, however, clearly associated with very early histopathological lesions and immunostaining with COL 2-3/4Cshort increased with progression of the latter. In contrast, type II collagen cleavage occurs throughout the articular cartilage at an early stage in collagen-induced arthritis.

Expression of collagen and aggrecan genes in normal and osteoarthritic murine knee joints.

OBJECTIVE: The STR/ort mouse strain develops osteoarthritis (OA) of the medial tibial cartilage whilst CBA mice do not develop this disease. We investigated whether changes occur in the expression of genes encoding major extracellular matrix proteins in the connective tissue of the murine knee joint in OA. DESIGN: Expression of the genes encoding collagens II (Col2alpha1), X (Col10alpha1), alpha2(XI) (Col11alpha2) and aggrecan (Agc) was detected in skeletally mature and immature male mice of the CBA and STR/ort strains by in situ hybridization. RESULTS: Col2alpha1 was expressed by chondrocytes of the tibial and patella-femoral cartilage and by the meniscal cartilage in all young mice (4-9 weeks) but only in the patella-femoral cartilage in older mice of both strains (36-45 weeks). In contrast Col2alpha1 was expressed by growth plate chondrocytes of both species at all ages. Similarly, Col2alpha1 transcripts were detected in cruciate ligament cells in both strains at all ages. Col10alpha1 transcripts were detected in cruciate ligament cells in both strains at all ages. Col10alpha1 expression was evident in the hypertrophic chondrocytes in the growth plate of young CBA and STR mice, but was not active in these cells in mature animals. However, Col10alpha1 was transcribed in articular chondrocytes of the tibia, meniscal and patella-femoral cartilages of all ages, in normal and osteoarthritic mice. Transcripts were also present in ligament of some mature animals. Col11alpha2 followed a similar pattern of expression in CBA cartilages to Col2alpha1, being active in adult growth plate but generally inactive in adult articular cartilages. Young CBA and STR/ort mice expressed Col11alpha2 in articular cartilage and very strongly throughout the growth plate. Agc expression was detected in all articular cartilages at all ages in both strains. Interestingly, transcripts for all four genes were absent in tibial articular chondrocytes located close to osteoarthritic lesions in STR/ort mice, indicating that these cells are unable to synthesize matrix proteins. Adult STR/ort mice also showed evidence of tissue remodeling around the periphery of the knee joint. Cells in remodeling areas actively transcribed Col2alpha1, Col10alpha1, Col11alpha2 and Agc. CONCLUSION: It is unlikely that OA develops in STR/ort mice because of failure to express major proteins in joint tissue. However, once lesions develop in articular cartilage neighbouring chondrocytes fail to express genes encoding several matrix proteins.

A knowledge-based multimedia telecare system to improve the provision of formal and informal care for the elderly and disabled.

We have developed a knowledge-based multimedia telecare system, based on a multimedia PC connected by ISDN at 128 kbit/s. The user display is a television. Multimedia material is accessed through a browser-based interface. A remote-control handset is used as the main means of interaction, to ensure ease of use and overcome any initial reservations resulting from 'technophobia' on the part of the informal carer. The system was used in 13 family homes and four professional sites in Northern Ireland. The evaluations produced positive comments from the informal carers. There are plans to expand the use of the system.

Clinical and economic evaluation of surgical treatments for faecal incontinence.

BACKGROUND: Faecal incontinence affects 1-2 per cent of the adult population. While many patients can be managed successfully with conservative therapy, a small proportion require surgery. Improved imaging techniques and technological advances have led to the availability of a wide range of surgical treatments. Decision-makers increasingly require clinical and cost-effectiveness studies of surgical treatments for faecal incontinence. This review examines the practical aspects of undertaking such studies. METHODS: The practical issues related to different aetiologies, different types of treatment, defining outcomes, the hidden costs of the condition and its treatment, the rapid changes in technology and issues of patient choice were all considered. A Medline search was undertaken to identify relevant publications, and the reference lists of identified papers were scanned manually. RESULTS: There are few randomized controlled studies and those that have been performed have been limited in their scope. There has also been very limited health economic analysis undertaken. Strategies for conducting such studies, and the criteria they use, have been outlined. CONCLUSION: Randomized trials have a limited role in this setting because of variations in aetiology, difficulty in standardizing procedures, continuing evolution of devices, small patient numbers, concerns for patient choice and the need for long-term follow-up. Issues to be addressed when evaluating interventions for faecal incontinence include choosing appropriate measures of surgical outcome, using new continence scoring systems and tools for quality-of-life assessment, and choosing appropriate cost perspectives and time horizons for economic evaluation.

Matrix metalloproteinases and aggrecanases cleave aggrecan in different zones of normal cartilage but colocalize in the development of osteoarthritic lesions in STR/ort mice.

OBJECTIVE: To map aggrecan cleavage by matrix metalloproteinases (MMPs) and aggrecanases in normal murine tibial articular cartilage (CBA strain) and in the development of spontaneous osteoarthritis (OA) in the STR/ort mouse and to assess the influence of sex hormone status on these conditions in gonadectomized STR/ort mice. METHODS: The distributions of neoepitopes of aggrecan generated by MMP (VDIPEN) and aggrecanase (NITEGE) cleavage were investigated by immunohistochemistry. RESULTS: VDIPEN neoepitope was detected mainly in the pericellular matrix of deep-zone chondrocytes in normal tibial cartilage from STR/ort and CBA mice. In early OA, VDIPEN immunostaining also localized to the pericellular matrix of chondrocytes at the site of the lesion. With increasing severity of OA lesions, VDIPEN immunostaining was also detected in the interterritorial matrix, close to the site of the lesion. In contrast, NITEGE mapped most strongly to the pericellular matrix of upper-zone chondrocytes in normal tibial cartilage. As with VDIPEN, NITEGE was strongly expressed in the pericellular matrix at the site of early OA lesions. With advancing OA, NITEGE colocalized with VDIPEN in both the pericellular and interterritorial matrices of chondrocytes adjacent to OA lesions and in those of the deep zones. Hormone status did not appear to influence the development of OA or the distribution of aggrecan neoepitopes in STR/ort mice. CONCLUSION: MMP- and aggrecanase-generated neoepitopes map predominantly to different regions in normal murine tibial cartilage. However, both groups of enzymes generate increased amounts of neoepitopes in pericellular and interterritorial matrix adjacent to histopathologic lesions of OA. Aggrecan degradation and the development of OA appear to be independent of sex hormone status in this model.

Development and definition of the role of the operating department nurse: a review.

In the current cost-conscious National Health Service (NHS), the role of the nurse during anaesthesia and surgery is one that has interested health service managers keen to know what happens behind the closed doors of the operating department. It is clear that if nurses working within this specialized setting are to secure a future in providing care for surgical patients, then it is important to clarify and articulate exactly what it is that their role involves. The aim of this paper is to examine the role of the operating department nurse. First, it will illustrate how the role of the nurse has evolved alongside medical and technical advances in surgery, particularly in the last century. Second, it will highlight that while definition of the role has received attention in the North American literature, references in the British literature as to what it is that operating department nurses do, are scant. Finally, it will address the evolving role of the contemporary perioperative nurse highlighting the changes and challenges that nurses who work within this setting are currently facing. It is suggested here that nurses need to engage in role definition in order to be clear about their direction for the future, particularly within the fast changing, technologically driven environment of the operating department.

Exploratory study of nursing in an operating department: preliminary findings on the role of the nurse.

This study was exploratory and describes how nursing was viewed and practised by nurses who worked in an operating department. It also highlighted factors that might influence the role performance of operating department nurses. The research involved interviews with a sample of 6 nurses working in an operating department, observation of 32 hours of nursing work over 6 operating sessions, in addition to the analysis of various documents, including the nursing care plans of 22 patients. Data were triangulated and analysed by constant comparison. Findings indicated that nurses had difficulty in articulating exactly what it was that operating department nursing entailed, but rather viewed their role in terms of the functions they performed. Observations indicated that the nursing role was primarily orientated toward the physical rather than the psychological aspects of care-giving. Furthermore, it appeared that the medical profession, nursing philosophy/leadership and the characteristics of patients all influenced the manner in which nurses enacted their role. These findings suggest that further research into the role of the nurse within the operating department environment is warranted. Key factors from this study were developed into a framework suitable for guiding future study of the nursing role in this environment.