Novel Glycomimetics Protect against Glycated Low-Density Lipoprotein-Induced Vascular Calcification In Vitro via Attenuation of the RAGE/ERK/CREB Pathway

Heparan sulphate (HS) can act as a co-receptor on the cell surface and alterations in this process underpin many pathological conditions. We have previously described the usefulness of mimics of HS (glycomimetics) in protection against β-glycerophosphate-induced vascular calcification and in the restoration of the functional capacity of diabetic endothelial colony-forming cells in vitro. This study aims to investigate whether our novel glycomimetic compounds can attenuate glycated low-density lipoprotein (g-LDL)-induced calcification by inhibiting RAGE signalling within the context of critical limb ischemia (CLI). We used an established osteogenic in vitro vascular smooth muscle cell (VSMC) model. Osteoprotegerin (OPG), sclerostin and glycation levels were all significantly increased in CLI serum compared to healthy controls, while the vascular calcification marker osteocalcin (OCN) was down-regulated in CLI patients vs. controls. Incubation with both CLI serum and g-LDL (10 µg/mL) significantly increased VSMC calcification vs. controls after 21 days, with CLI serum-induced calcification apparent after only 10 days. Glycomimetics (C2 and C3) significantly inhibited g-LDL and CLI serum-induced mineralisation, as shown by a reduction in alizarin red (AR) staining and alkaline phosphatase (ALP) activity. Furthermore, secretion of the osteogenic marker OCN was significantly reduced in VSMCs incubated with CLI serum in the presence of glycomimetics. Phosphorylation of cyclic AMP response element-binding protein (CREB) was significantly increased in g-LDL-treated cells vs. untreated controls, which was attenuated with glycomimetics. Blocking CREB activation with a pharmacological inhibitor 666-15 replicated the protective effects of glycomimetics, evidenced by elevated AR staining. In silico molecular docking simulations revealed the binding affinity of the glycomimetics C2 and C3 with the V domain of RAGE. In conclusion, these findings demonstrate that novel glycomimetics, C2 and C3 have potent anti-calcification properties in vitro, inhibiting both g-LDL and CLI serum-induced VSMC mineralisation via the inhibition of LDLR, RAGE, CREB and subsequent expression of the downstream osteogenic markers, ALP and OCN.

Skeletal and extraskeletal disorders of biomineralization

The physiological process of biomineralization is complex and deviation from it leads to a variety of diseases. Progress in the past 10 years has enhanced understanding of the genetic, molecular and cellular pathophysiology underlying these disorders; sometimes, this knowledge has both facilitated restoration of health and clarified the very nature of biomineralization as it occurs in humans. In this Review, we consider the principal regulators of mineralization and crystallization, and how dysregulation of these processes can lead to human disease. The knowledge acquired to date and gaps still to be filled are highlighted. The disorders of mineralization discussed comprise a broad spectrum of conditions that encompass bone disorders associated with alterations of mineral quantity and quality, as well as disorders of extraskeletal mineralization (hyperphosphataemic familial tumoural calcinosis). Included are disorders of alkaline phosphatase (hypophosphatasia) and phosphate homeostasis (X-linked hypophosphataemic rickets, fluorosis, rickets and osteomalacia). Furthermore, crystallopathies are covered as well as arterial and renal calcification. This Review discusses the current knowledge of biomineralization derived from basic and clinical research and points to future studies that will lead to new therapeutic approaches for biomineralization disorders.

Leucine-Rich α-2-Glycoprotein 1 Suppresses Endothelial Cell Activation Through ADAM10-Mediated Shedding of TNF-α Receptor

Elevated serum concentrations of leucine-rich α-2-glycoprotein (LRG1) have been reported in patients with inflammatory, autoimmune, and cardiovascular diseases. This study aims to investigate the role of LRG1 in endothelial activation. LRG1 in endothelial cells (ECs) of arteries and serum of patients with critical limb ischemia (CLI) was assessed by immunohistochemistry and ELISA, respectively. LRG1 expression in sheared and tumor necrosis factor-α (TNF-α)-treated ECs was analyzed. The mechanistic role of LRG1 in endothelial activation was studied in vitro. Plasma of 37-week-old Lrg1 ^-/- mice was used to investigate causality between LRG1 and tumor necrosis factor receptor 1 (TNFR1) shedding. LRG1 was highly expressed in ECs of stenotic but not normal arteries. LRG1 concentrations in serum of patients with CLI were elevated compared to healthy controls. LRG1 expression was shear dependent. It could be induced by TNF-α, and the induction of its expression was mediated by NF-κB activation. LRG1 inhibited TNF-α-induced activation of NF-κB signaling, expression of VCAM-1 and ICAM-1, and monocyte capture, firm adhesion, and transendothelial migration. Mechanistically, LRG1 exerted its function by causing the shedding of TNFR1 via the ALK5-SMAD2 pathway and the subsequent activation of ADAM10. Consistent with this mechanism, LRG1 and sTNFR1 concentrations were correlated in the serum of CLI patients. Causality between LRG1 and TNFR1 shedding was established by showing that Lrg1 ^-/- mice had lower plasma sTNFR1 concentrations than wild type mice. Our results demonstrate a novel role for LRG1 in endothelial activation and its potential therapeutic role in inflammatory diseases should be investigated further.

Loss of SIRT1 in diabetes accelerates DNA damage-induced vascular calcification

AIMS

Vascular calcification is a recognized predictor of cardiovascular risk in the diabetic patient, with DNA damage and accelerated senescence linked to oxidative stress-associated pathological calcification. Having previously shown that systemic SIRT1 is reduced in diabetes, the aim was to establish whether SIRT1 is protective against a DNA damage-induced senescent and calcified phenotype in diabetic vascular smooth muscle cells (vSMCs).

METHODS AND RESULTS

Immunohistochemistry revealed decreased SIRT1 and increased DNA damage marker expression in diabetic calcified arteries compared to non-diabetic and non-calcified controls, strengthened by findings that vSMCs isolated from diabetic patients show elevated DNA damage and senescence, assessed by the Comet assay and telomere length. Hyperglycaemic conditions were used and induced DNA damage and enhanced senescence in vSMCs in vitro. Using H2O2 as a model of oxidative stress-induced DNA damage, pharmacological activation of SIRT1 reduced H2O2 DNA damage-induced calcification, prevented not only DNA damage, as shown by reduced comet tail length, but also decreased yH2AX foci formation, and attenuated calcification. While Ataxia Telanglectasia Mutated (ATM) expression was reduced following DNA damage, in contrast, SIRT1 activation significantly increased ATM expression, phosphorylating both MRE11 and NBS1, thus allowing formation of the MRN complex and increasing activation of the DNA repair pathway.

CONCLUSION

DNA damage-induced calcification is accelerated within a diabetic environment and can be attenuated in vitro by SIRT1 activation. This occurs through enhancement of the MRN repair complex within vSMCs and has therapeutic potential within the diabetic patient.

NR4A Nuclear Receptors Target Poly-ADP-Ribosylated DNA-PKcs Protein to Promote DNA Repair

Although poly-ADP-ribosylation (PARylation) of DNA repair factors had been well documented, its role in the repair of DNA double-strand breaks (DSBs) is poorly understood. NR4A nuclear orphan receptors were previously linked to DSB repair; however, their function in the process remains elusive. Classically, NR4As function as transcription factors using a specialized tandem zinc-finger DNA-binding domain (DBD) for target gene induction. Here, we show that NR4A DBD is bi-functional and can bind poly-ADP-ribose (PAR) through a pocket localized in the second zinc finger. Separation-of-function mutants demonstrate that NR4A PAR binding, while dispensable for transcriptional activity, facilitates repair of radiation-induced DNA double-strand breaks in G1. Moreover, we define DNA-PKcs protein as a prominent target of ionizing radiation-induced PARylation. Mechanistically, NR4As function by directly targeting poly-ADP-ribosylated DNA-PKcs to facilitate its autophosphorylation-promoting DNA-PK kinase assembly at DNA lesions. Selective targeting of the PAR-binding pocket of NR4A presents an opportunity for cancer therapy.

p17 from HIV induces brain endothelial cell angiogenesis through EGFR-1-mediated cell signalling activation

HIV-associated neurocognitive disorder in HIV patients substantially reduces their quality of life. We previously showed that the HIV matrix protein, p17 could stimulate lymph-angiogenesis in vitro potentially contributing to lymphoma tumour growth and in addition is associated with vascular activation in neuro-degenerating brain tissue; here, therefore, we have investigated the detailed molecular mechanisms of this action. We performed in vitro cell culture, angiogenesis experiments, phospho-protein microarrays and Western blotting to identify cellular signalling induced by p17 within human brain endothelial cells (HbMEC), and inhibitor studies to block p17-induced vascular growth. We also characterised the effects of hippocampal CA1 injection of p17 on epidermal growth factor receptor-1 (EGFR1) expression linked to our murine model of dementia. p17 strongly induced angiogenesis of HbMEC (migration, tube formation and spheroid growth). p17 concomitantly increased phosphorylation of EGFR1 as well as down-stream intermediates ERK1/2, FAK, PLC-γ and PKC-β whilst an inhibitor peptide of EGFR, blocked cell signalling and angiogenesis. Finally, Mice that showed reduced cognitive function and behavioural deficiencies after p17 injection, demonstrated that p17 localised in cortical microvessels and also neurones many of which stained positive for p-EGFR1 by histology/IHC. This work provides strong support that p17 may be involved in initiating and/or perpetuating vascular tissue pathophysiology associated with comorbidity in HIV patients.

Suppression of SIRT1 in Diabetic Conditions Induces Osteogenic Differentiation of Human Vascular Smooth Muscle Cells via RUNX2 Signalling

Vascular calcification is associated with significant morbidity and mortality within diabetes, involving activation of osteogenic regulators and transcription factors. Recent evidence demonstrates the beneficial role of Sirtuin 1 (SIRT1), an NAD⁺ dependant deacetylase, in improved insulin sensitivity and glucose homeostasis, linking hyperglycaemia and SIRT1 downregulation. This study aimed to determine the role of SIRT1 in vascular smooth muscle cell (vSMC) calcification within the diabetic environment. An 80% reduction in SIRT1 levels was observed in patients with diabetes, both in serum and the arterial smooth muscle layer, whilst both RUNX2 and Osteocalcin levels were elevated. Human vSMCs exposed to hyperglycaemic conditions in vitro demonstrated enhanced calcification, which was positively associated with the induction of cellular senescence, verified by senescence-associated β-galactosidase activity and cell cycle markers p16 and p21. Activation of SIRT1 by SRT1720 reduced Alizarin red staining by a third, via inhibition of the RUNX2 pathway and prevention of senescence. Conversely, inhibition of SIRT1 via Sirtinol and siRNA increased RUNX2 by over 50%. These findings demonstrate the key role that SIRT1 plays in preventing calcification in a diabetic environment, through the inhibition of RUNX2 and senescence pathways, suggesting a downregulation of SIRT1 may be responsible for perpetuating vascular calcification in diabetes.

The Interplay of SIRT1 and Wnt Signaling in Vascular Calcification

Vascular calcification is a major health risk and is highly correlated with atherosclerosis, diabetes, and chronic kidney disease. The development of vascular calcification is an active and complex process linked with a multitude of signaling pathways, which regulate promoters and inhibitors of osteogenesis, the balance of which become deregulated in disease conditions. SIRT1, a protein deacetylase, known to be protective in inhibiting oxidative stress and inflammation within the vessel wall, has been shown as a possible key player in modulating the cell-fate determining canonical Wnt signaling pathways. Suppression of SIRT1 has been reported in patients suffering with cardiovascular pathologies, suggesting that the sustained acetylation of osteogenic factors could contribute to their activation and in turn, lead to the progression of calcification. There is clear evidence of the synergy between β-Catenin and elevated Runx2, and with Wnt signaling being β-Catenin dependent, further understanding is needed as to how these molecular pathways converge and interact, in order to provide novel insight into the mechanism by which smooth muscle cells switch to an osteogenic differentiation programme. Therefore, this review will describe the current concepts of pathological soft tissue mineralization, with a focus on the contribution of SIRT1 as a regulator of Wnt signaling and its targets, discussing SIRT1 as a potential target for manipulation and therapy.

Links between a biomarker profile, cold ischaemic time and clinical outcome following simultaneous pancreas and kidney transplantation

In sepsis, trauma and major surgery, where an explicit physiological insult leads to a significant systemic inflammatory response, the acute evolution of biomarkers have been delineated. In these settings, Interleukin (IL) -6 and TNF-α are often the first pro-inflammatory markers to rise, stimulating production of acute phase proteins followed by peaks in anti-inflammatory markers. Patients undergoing SPKT as a result of diabetic complications already have an inflammatory phenotype as a result of uraemia and glycaemia. How this inflammatory response is affected further by the trauma of major transplant surgery and how this may impact on graft survival is unknown, despite the recognised pro-inflammatory cytokines' detrimental effects on islet cell function. The aim of the study was to determine the evolution of biomarkers in omentum and serum in the peri-operative period following SPKT. The biochemical findings were correlated to clinical outcomes. Two omental biopsies were taken (at the beginning and end of surgery) and measured for CD68+ and CD206+ antibodies (M1 and M2 macrophages respectively). Serum was measured within the first 72 h post-SPKT for pro- and anti-inflammatory cytokines (IL -6, -10 and TNF-α), inflammatory markers (WCC and CRP) and endocrine markers (insulin, C-peptide, glucagon and resistin). 46 patients were recruited to the study. Levels of M1 (CD68+) and M2 (CD206+) macrophages were significantly raised at the end of surgery compared to the beginning (p = 0.003 and p < 0.001 respectively). Levels of C-peptide, insulin and glucagon were significantly raised 30 min post pancreas perfusion compared to baseline and were also significantly negatively related to prolonged cold ischaemic time (CIT) (p < 0.05). CRP levels correlated significantly with the Post-Operative Morbidity Survey (p < 0.05). The temporal inflammatory marker signature after SPKT is comparable to the pattern observed following other physiological insults. Unique to this study, we find that CIT is significantly related to early pancreatic endocrine function. In addition, this study suggests a predictive value of CRP in peri-operative morbidity following SPKT.

HIV-1 matrix protein p17 misfolding forms toxic amyloidogenic assemblies that induce neurocognitive disorders

Human immunodeficiency virus type-1 (HIV-1)-associated neurocognitive disorder (HAND) remains an important neurological manifestation that adversely affects a patient’s quality of life. HIV-1 matrix protein p17 (p17) has been detected in autoptic brain tissue of HAND individuals who presented early with severe AIDS encephalopathy. We hypothesised that the ability of p17 to misfold may result in the generation of toxic assemblies in the brain and may be relevant for HAND pathogenesis. A multidisciplinary integrated approach has been applied to determine the ability of p17 to form soluble amyloidogenic assemblies in vitro. To provide new information into the potential pathogenic role of soluble p17 species in HAND, their toxicological capability was evaluated in vivo. In C. elegans, capable of recognising toxic assemblies of amyloidogenic proteins, p17 induces a specific toxic effect which can be counteracted by tetracyclines, drugs able to hinder the formation of large oligomers and consequently amyloid fibrils. The intrahippocampal injection of p17 in mice reduces their cognitive function and induces behavioral deficiencies. These findings offer a new way of thinking about the possible cause of neurodegeneration in HIV-1-seropositive patients, which engages the ability of p17 to form soluble toxic assemblies.

Up-regulation of serotonin receptor 2B mRNA and protein in the peri-infarcted area of aged rats and stroke patients

Despite the fact that a high proportion of elderly stroke patients develop mood disorders, the mechanisms underlying late-onset neuropsychiatric and neurocognitive symptoms have so far received little attention in the field of neurobiology. In rodents, aged animals display depressive symptoms following stroke, whereas young animals recover fairly well. This finding has prompted us to investigate the expression of serotonin receptors 2A and 2B, which are directly linked to depression, in the brains of aged and young rats following stroke. Although the development of the infarct was more rapid in aged rats in the first 3 days after stroke, by day 14 the cortical infarcts were similar in size in both age groups i.e. 45% of total cortical volume in young rats and 55.7% in aged rats. We also found that the expression of serotonin receptor type B mRNA was markedly increased in the perilesional area of aged rats as compared to the younger counterparts. Furthermore, histologically, HTR2B protein expression in degenerating neurons was closely associated with activated microglia both in aged rats and human subjects. Treatment with fluoxetine attenuated the expression of Htr2B mRNA, stimulated post-stroke neurogenesis in the subventricular zone and was associated with an improved anhedonic behavior and an increased activity in the forced swim test in aged animals. We hypothesize that HTR2B expression in the infarcted territory may render degenerating neurons susceptible to attack by activated microglia and thus aggravate the consequences of stroke.

Clinical management and research priorities for high-risk prostate cancer in the UK: Meeting report of a multidisciplinary panel in conjunction with the NCRI Prostate Cancer Clinical Studies Localised Subgroup

The management of high-risk prostate cancer has become increasingly sophisticated, with refinements in radical therapy and the inclusion of adjuvant local and systemic therapies. Despite this, high-risk prostate cancer continues to have significant treatment failure rates, with progression to metastasis, castrate resistance and ultimately disease-specific death. In an effort to discuss the challenges in this field, the UK National Clinical Research Institute’s Prostate Cancer Clinical Studies localised subgroup convened a multidisciplinary national meeting in the autumn of 2014. The remit of the meeting was to debate and reach a consensus on the key clinical and research challenges in high-risk prostate cancer and to identify themes that the UK would be best placed to pursue to help improve outcomes. This report presents the outcome of those discussions and the key recommendations for future research in this highly heterogeneous disease entity.

Elevated levels of endothelial-derived microparticles, and serum CXCL9 and SCGF-β are associated with unstable asymptomatic carotid plaques

Endothelial microparticles (EMPs) are released from dysfunctional endothelial cells. We hypothesised that patients with unstable carotid plaque have higher levels of circulating microparticles compared to patients with stable plaques, and may correlate with serum markers of plaque instability and inflammation. Circulating EMPs, platelet MPs (PMPs) and inflammatory markers were measured in healthy controls and patients undergoing carotid endarterectomy. EMP/PMPs were quantified using flow cytometry. Bioplex assays profiled systemic inflammatory and bone-related proteins. Immunohistological analysis detailed the contribution of differentially-regulated systemic markers to plaque pathology. Alizarin red staining showed calcification. EMPs and PMPs were significantly higher in patients with carotid stenosis (≥70%) compared to controls, with no differences between asymptomatic vs symptomatic patients. Asymptomatic patients with unstable plaques exhibited higher levels of EMPs, CXCL9 and SCGF-β compared to those with stable plaques. CXCL9, and SCGF-β were detected within all plaques, suggesting a contribution to both localised and systemic inflammation. Osteopontin and osteoprotegerin were significantly elevated in the symptomatic vs asymptomatic group, while osteocalcin was higher in asymptomatic patients with stable plaque. All plaques exhibited calcification, which was significantly greater in asymptomatic patients. This may impact on plaque stability. These data could be important in identifying patients at most benefit from intervention.

Monomeric C-reactive protein--a key molecule driving development of Alzheimer's disease associated with brain ischaemia?

Alzheimer’s disease (AD) increases dramatically in patients with ischaemic stroke. Monomeric C-reactive protein (mCRP) appears in the ECM of ischaemic tissue after stroke, associating with microvasculature, neurons and AD-plaques, Aβ, also, being able to dissociate native-CRP into inflammatory, mCRP in vivo. Here, mCRP injected into the hippocampal region of mice was retained within the retrosplenial tract of the dorsal 3rd ventrical and surrounding major vessels. Mice developed behavioural/cognitive deficits within 1 month, concomitant with mCRP staining within abnormal looking neurons expressing p-tau and in beta-amyloid 1-42-plaque positive regions. mCRP co-localised with CD105 in microvessels suggesting angiogenesis. Phospho-arrays/Western blotting identified signalling activation in endothelial cells and neurons through p-IRS-1, p-Tau and p-ERK1/2-which was blocked following pre-incubation with mCRP-antibody. mCRP increased vascular monolayer permeability and gap junctions, increased NCAM expression and produced haemorrhagic angiogenesis in mouse matrigel implants. mCRP induced tau244–372 aggregation and assembly in vitro. IHC study of human AD/stroke patients revealed co-localization of mCRP with Aβ plaques, tau-like fibrils and IRS-1/P-Tau positive neurons and high mCRP-levels spreading from infarcted core regions matched reduced expression of Aβ/Tau. mCRP may be responsible for promoting dementia after ischaemia and mCRP clearance could inform therapeutic avenues to reduce the risk of future dementia.

Endothelial microparticles as conveyors of information in atherosclerotic disease

Endothelial microparticles (EMPs) are complex submicron membrane-shed vesicles released into the circulation following endothelium cell activation or apoptosis. They are classified as either physiological or pathological, with anticoagulant or pro-inflammatory effects respectively. Endothelial dysfunction caused by inflammation is a key initiating event in atherosclerotic plaque formation. Athero-emboli, resulting from ruptured carotid plaques are a major cause of stroke. Current clinical techniques for arterial assessment, angiography and carotid ultrasound, give accurate information about stenosis but limited evidence on plaque composition, inflammation or vulnerability; as a result, patients with asymptomatic, or fragile carotid lesions, may not be identified and treated effectively. There is a need to discover novel biomarkers and develop more efficient diagnostic approaches in order to stratify patients at most risk of stroke, who would benefit from interventional surgery. Increasing evidence suggests that EMPs play an important role in the pathogenesis of cardiovascular disease, acting as a marker of damage, either exacerbating disease progression or triggering a repair response. In this regard, it has been suggested that EMPs have the potential to act as biomarkers of disease status. In this review, we will present the evidence to support this hypothesis and propose a novel concept for the development of a diagnostic device that could be implemented in the clinic.

Testicular microlithiasis: is it significant?

Previously considered to be a benign finding on scrotal ultrasonography, testicular microlithiasis (TM) is now recognized as a condition associated with the development of testicular neoplasia. Despite this the management of TM remains unclear. We review the evidence for this association and suggested management strategies.

Deficiency of terminal ADP-ribose protein glycohydrolase TARG1/C6orf130 in neurodegenerative disease

Adenosine diphosphate (ADP)-ribosylation is a post-translational protein modification implicated in the regulation of a range of cellular processes. A family of proteins that catalyse ADP-ribosylation reactions are the poly(ADP-ribose) (PAR) polymerases (PARPs). PARPs covalently attach an ADP-ribose nucleotide to target proteins and some PARP family members can subsequently add additional ADP-ribose units to generate a PAR chain. The hydrolysis of PAR chains is catalysed by PAR glycohydrolase (PARG). PARG is unable to cleave the mono(ADP-ribose) unit directly linked to the protein and although the enzymatic activity that catalyses this reaction has been detected in mammalian cell extracts, the protein(s) responsible remain unknown. Here, we report the homozygous mutation of the c6orf130 gene in patients with severe neurodegeneration, and identify C6orf130 as a PARP-interacting protein that removes mono(ADP-ribosyl)ation on glutamate amino acid residues in PARP-modified proteins. X-ray structures and biochemical analysis of C6orf130 suggest a mechanism of catalytic reversal involving a transient C6orf130 lysyl-(ADP-ribose) intermediate. Furthermore, depletion of C6orf130 protein in cells leads to proliferation and DNA repair defects. Collectively, our data suggest that C6orf130 enzymatic activity has a role in the turnover and recycling of protein ADP-ribosylation, and we have implicated the importance of this protein in supporting normal cellular function in humans.

ZRANB3 is a structure-specific ATP-dependent endonuclease involved in replication stress response

To efficiently duplicate their genomic content, cells must overcome DNA lesions that interfere with processive DNA replication. These lesions may be removed and repaired, rather than just tolerated, to allow continuity of DNA replication on an undamaged DNA template. However, it is unclear how this is achieved at a molecular level. Here we identify a new replication-associated factor, ZRANB3 (zinc finger, RAN-binding domain containing 3), and propose its role in the repair of replication-blocking lesions. ZRANB3 has a unique structure-specific endonuclease activity, which is coupled to ATP hydrolysis. It cleaves branched DNA structures with unusual polarity, generating an accessible 3'-OH group in the template of the leading strand. Furthermore, ZRANB3 localizes to DNA replication sites and interacts with the components of the replication machinery. It is recruited to damaged replication forks via multiple mechanisms, which involve interactions with PCNA, K63-polyubiquitin chains, and branched DNA structures. Collectively, our data support a role for ZRANB3 in the replication stress response and suggest new insights into how DNA repair is coordinated with DNA replication to maintain genome stability.

Pharmacokinetic and safety profile of raltegravir and ribavirin, when dosed separately and together, in healthy volunteers

BACKGROUND

Treatment of chronic hepatitis C virus (HCV) infection in HIV-1-co-infected individuals remains challenging due to numerous factors, including drug-drug interactions. The aim of this study was to assess the safety and pharmacokinetic (PK) profile of raltegravir and ribavirin when dosed separately and together.

METHODS

Fourteen healthy volunteers [mean (standard deviation) age 35 (10) years, 71% male] entered this phase 1 PK study and received single-dose ribavirin (800 mg) on day 1 (phase 1). Following a washout period, subjects received raltegravir (400 mg twice daily) on days 15-19 (phase 2) and single-dose ribavirin (800 mg) with raltegravir (400 mg) on day 20 (phase 3). Intensive PK sampling was undertaken on days 1, 19 and 20 and differences in geometric mean ratios (GMRs) for PK parameters between study periods were assessed.

RESULTS

No statistically significant differences in PK parameters were observed for raltegravir between phases 2 and 3. A statistically significant decrease in maximum plasma concentration (C(max)) and an increase in time to maximum plasma concentration (T(max)) were observed for ribavirin in phase 3 compared with phase 1 [GMR (95% confidence interval) 0.79 (0.62-1.00) and 1.39 (1.08-1.78), respectively], whereas no significant differences in other ribavirin PK parameters were observed between study phases. No clinically significant safety concerns were reported.

CONCLUSIONS

The PK profile of ribavirin is altered when administered with raltegravir (reduced C(max) and increased T(max)), with no safety concerns identified. This is unlikely to be of clinical significance or have an impact on the antiviral effects of ribavirin in HIV-1- and HCV-co-infected subjects.

DNA repair factor APLF is a histone chaperone

Poly(ADP-ribosyl)ation plays a major role in DNA repair, where it regulates chromatin relaxation as one of the critical events in the repair process. However, the molecular mechanism by which poly(ADP-ribose) modulates chromatin remains poorly understood. Here we identify the poly(ADP-ribose)-regulated protein APLF as a DNA-damage-specific histone chaperone. APLF preferentially binds to the histone H3/H4 tetramer via its C-terminal acidic motif, which is homologous to the motif conserved in the histone chaperones of the NAP1L family (NAP1L motif). We further demonstrate that APLF exhibits histone chaperone activities in a manner that is dependent on its acidic domain and that the NAP1L motif is critical for the repair capacity of APLF in vivo. Finally, we identify structural analogs of APLF in lower eukaryotes with the ability to bind histones and localize to the sites of DNA-damage-induced poly(ADP-ribosyl)ation. Collectively, these findings define the involvement of histone chaperones in poly(ADP-ribose)-regulated DNA repair reactions.

Measuring patient satisfaction in sexually transmitted infection clinics: a systematic review

OBJECTIVES

Measuring patient satisfaction is an important aspect of making services attractive to patients and improving service delivery, and outpatient-based clinics are increasingly assessing service quality using patient-based outcome measures. No systematic review of patient satisfaction in sexually transmitted infection clinics has previously been performed. The objectives of the review were: (1) to establish how patient satisfaction with sexual health services has been defined and measured; (2) to identify whether a "gold standard" method exists; and (3) to identify the themes regarded by patients as priorities for delivering a quality service within a sexually transmitted infection clinic setting.

METHODS

A search of eight electronic journal databases and unpublished data sources was used to identify studies measuring patient satisfaction in a sexually transmitted infection clinic setting. Following initial review of each abstract, data from eligible studies were extracted by two independent reviewers and content analysis used to identify common themes.

RESULTS

Eighteen questionnaire-based studies, nine semistructured interviews and four other studies, including three focus groups, fulfilled the selection criteria for inclusion. Three studies incorporated more than one method of analysis. No common validated method of assessing patient satisfaction was identified. Themes reported to be of greatest importance were the convenience of clinic location, availability of appointments, staff attitude to patients, effective provision of information and maintenance of confidentiality.

CONCLUSIONS

This review has identified the need for a validated and standardised approach to assess patient satisfaction in sexually transmitted infection clinics. Comparing studies which have measured satisfaction, clear themes for the provision of a high quality service, from a patient perspective, have emerged. These themes should be incorporated into assessment tools, such as questionnaires, when reviewing service delivery.

Immediate dual energy X-ray absorptiometry reveals a high incidence of osteoporosis in patients with advanced prostate cancer before hormonal manipulation

OBJECTIVE

To examine the incidence of osteoporosis in patients with advanced prostate cancer (using forearm densitometry) before commencing androgen deprivation therapy (ADT), as osteoporotic fractures are more frequent in patients with prostate cancer who have undergone either medical or surgical castration, because of rapid loss of bone mass.

PATIENTS AND METHODS

In all, 174 patients (mean age 74.6 years, range 46-90) with advanced prostate cancer presented over 2 years. Their forearm bone densitometry values were compared with those from 106 age-matched controls (mean age 74.3 years, range 66-90).

RESULTS

Of the 174 patients, 73 (42%) were osteoporotic (t score <or=- 2.5) and 65 (37%) were osteopenic (t score - 1 to - 2.4). This compares with a 27% incidence of osteoporosis in the control group (P = 0.022). There were also no significant correlations between prostate specific antigen levels, Gleason score, tumour stage, biochemical markers and the presence or absence of osteoporosis risk factors.

CONCLUSION

Patients with advanced prostate cancer requiring ADT have a high incidence of osteoporosis before treatment. In addition, osteoporosis in these men cannot be predicted from clinical or biochemical values. Therefore, bone densitometry should be used in all patients with advanced cancer requiring ADT, as the results have implications for the choice of cancer therapy and the prophylaxis for osteoporosis.

A molecular phylogenetic analysis of reproductive trait evolution in the soft coral genus Alcyonium

The soft coral genus Alcyonium is among the most reproductively diverse invertebrate taxa known: The genus includes species that vary both in mode of reproduction (including broadcast spawners, internal brooders, and external brooders) and sexual expression (gonochores, hermaphrodites, and a unisexual parthenogen). Such diversity offers a unique opportunity to examine associations between reproductive and morphological traits in a phylogenetic context. We used an approximately 900-bp sequence of the nuclear ribosomal gene complex spanning the internal transcribed spacer (ITS) regions to construct a molecular phylogeny for 14 European and North American species of Alcyonium onto which we mapped the known distribution of reproductive and morphological traits. The phylogeny suggests that hermaphroditism or parthenogenesis has evolved independently at least twice in this genus, and always in internally brooding species. Broadcast spawning and external brooding only occur in species with large colony size, whereas all species with small colony size brood their larvae internally. Internal brooding and small size appear to be ancestral in this genus; if this is the case, an association between broadcast spawning and large colony size has evolved independently in at least two clades. This tendency of small adults to brood their larvae while large adults broadcast spawn them into the plankton has been observed in a variety of solitary invertebrate taxa, but to date has not been documented in any other colonial invertebrates. Moreoever, it has been suggested that organisms with a colonial growth form should not experience the allometric constraints on brood space that have been proposed to explain the association between adult size and mode of reproduction in solitary organisms. Unlike many other colonial groups, however, module (polyp) size is strongly correlated with colony size in Alcyonium, and constraints on brooding may be imposed by module, rather than colony, allometry. The very close genetic relationship (< 1% sequence divergence) and shared polymorphisms among A. digitatum (a large, gonochoric broadcast spawner), A. siderium, and A. sp. A (intermediate-sized and small hermaphroditic, internal brooders) suggest that evolutionary transitions between broadcast spawning and brooding and between gonochorism and hermaphroditism can occur easily and rapidly in this group.

Cervical cancer and sexual lifestyle: a systematic review of health education interventions targeted at women

A systematic review was conducted to determine the effectiveness of health education interventions to promote sexual risk reduction behaviours amongst women in order to reduce transmission of human papillomavirus (HPV), a leading agent in the development of cervical cancer. A comprehensive search was conducted to identify relevant studies. Studies were included in the review if they evaluated educational interventions targeting women only and measured the impact on either a behavioural outcome such as condom use for sexual intercourse, partner reduction or abstinence, or a clinical outcome such as incidence of a STD. Thirty studies met the inclusion criteria for the review; all had the primary aim of preventing HIV and other STDs rather than cervical cancer. Ten of the 30 studies were considered to provide the strongest evidence for a causal relationship between the intervention and the change in outcomes measured. Each of these 10 most rigorous studies showed a statistically significant positive effect on sexual risk reduction, typically with increased use of condoms for vaginal intercourse. This positive effect was generally sustained up to 3 months after intervention. It was concluded that educational interventions targeting socially and economically disadvantaged women in which information provision is complemented by sexual negotiation skill development can encourage at least short-term sexual risk reduction behaviour. This effect has the potential to reduce the transmission of HPV and thus possibly reduce the incidence of cervical carcinoma.

Interventions for encouraging sexual lifestyles and behaviours intended to prevent cervical cancer

BACKGROUND

Cervical cancer is one of the most common cancers affecting women world-wide. Prevention falls into two main categories - primary and secondary. Primary prevention is characterised by health promotion to promote lifestyles and behaviours minimising risk of cervical cancer. Interventions to promote the use of condoms for sexual intercourse (especially early intercourse amongst young women), sexual partner reduction, and negotiated safer sex strategies has been recommended as one approach to limit the spread of Human Papilloma Virus (HPV), one of the major risk factors for cervical cancer.

OBJECTIVES

To determine the effectiveness of health education interventions to promote sexual risk reduction behaviours amongst women in order to reduce transmission of HPV.

SEARCH STRATEGY

Electronic searching of EMBASE, ERIC, MEDLINE, PsycLIT, Social Science Citation Index and the CCTR were undertaken using a highly sensitive search strategy. Hand-searching took place of selected journals and reference lists.

SELECTION CRITERIA

Studies were included if they evaluated educational interventions targeting women only, and measured the impact on : either a behavioural outcome such as condom use for sexual intercourse, partner reduction, or abstinence; or a clinical outcome such as incidence of a sexually transmitted disease (STD).

DATA COLLECTION AND ANALYSIS

Data were extracted and methodological quality was assessed independently by two reviewers and any discrepancies were resolved between them. Ten per cent of the total number of studies were reviewed additionally by a third reviewer as a quality check and differences in judgement were resolved accordingly.

MAIN RESULTS

Thirty trials met the inclusion criteria for the review. All of them had the primary aim of preventing HIV and other STDs rather than cervical cancer. Four core methodological qualities were present in 10 of the 30 studies and constitute the subset from which potentially reliable conclusions may be drawn. Each of the 10 studies showed a statistically significant positive effect on sexual risk reduction, typically with increased use of condoms for vaginal intercourse. This positive effect was generally sustained up to three months after intervention.

REVIEWER'S CONCLUSIONS

Educational interventions targeting socially and economically disadvantaged women in which information provision is complemented by sexual negotiation skill development can encourage at least short-term sexual risk reduction behaviour. This has the potential to reduce the transmission of HPV, thus possibly reduce the incidence of cervical carcinoma.