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Ian J Frew,Claudio R Thoma,Strahil Georgiev,Andrea Minola,Manuela Hitz,Matteo Montani,Holger Moch,Wilhelm Krek In patients with von Hippel-Lindau (VHL) disease, renal cysts and clear cell renal cell carcinoma (ccRCC) arise from renal tubular epithelial cells containing biallelic inactivation of the VHL tumour suppressor gene. However, it is presumed that formation of renal cysts and their conversion to ccRC... ( view more )C involve additional genetic changes at other loci. Here, we show that cystic lesions in the kidneys of patients with VHL disease also demonstrate activation of the phosphatidylinositol-3-kinase (PI3K) pathway. Strikingly, combined conditional inactivation of Vhlh and the Pten tumour suppressor gene, which normally antagonises PI3K signalling, in the mouse kidney, elicits cyst formation after short latency, whereas inactivation of either tumour suppressor gene alone failed to produce such a phenotype. Interestingly, cells lining these cysts frequently lack a primary cilium, a microtubule-based cellular antenna important for suppression of uncontrolled kidney epithelial cell proliferation and cyst formation. Our results support a model in which the PTEN tumour suppressor protein cooperates with pVHL to suppress cyst development in the kidney. ( view less ) Robert Frew,Yushan Wang,Tracy M Weiss,Peggy Nelson,Thomas W Sawyer The highly potent marine toxin maitotoxin (MTX) evoked an increase in cytosolic Ca(2+) levels in fura-2 loaded rat aortic smooth muscle cells, which was dependent on extracellular Ca(2+). This increase was almost fully inhibited by KB-R7943, a potent selective inhibitor of the reverse mode of the N... ( view more )a(+)/Ca(2+) exchanger (NCX). Cell viability was assessed using ethidium bromide uptake and the alamarBlue cytotoxicity assay. In both assays MTX-induced toxicity was attenuated by KB-R7943, as well as by MDL 28170, a membrane permeable calpain inhibitor. Maitotoxin-evoked contractions of rat aortic strip preparations in vitro, which persist following washout of the toxin, were relaxed by subsequent addition of KB-R7943 or MDL 28170, either in the presence of, or following washout of MTX. These results suggest that MTX targets the Na(+)/Ca(2+) exchanger and causes it to operate in reverse mode (Na(+) efflux/Ca(2+) influx), thus leading to calpain activation, NCX cleavage, secondary Ca(2+) overload and cell death. ( view less ) E Albon,A Tsourapas,E Frew,C Davenport,F Oyebode,S Bayliss,T Arvanitis,C Meads OBJECTIVES: To establish the clinical effectiveness and cost-effectiveness of structural neuroimaging [structural magnetic resonance imaging (MRI) or computed tomography (CT) scanning] for all patients with psychosis, particularly a first episode of psychosis, relative to the current UK practice of... ( view more ) selective screening only where it is clinically indicated. DATA SOURCES: Major electronic databases were searched from inception to November 2006. REVIEW METHODS: A systematic review of studies reporting the additional diagnostic benefit of structural MRI, CT or combinations of these in patients with psychosis was conducted. The economic assessment consisted of a systematic review of economic evaluations and the development of a threshold analysis to predict the gain in quality-adjusted life-years (QALYs) required to make neuroimaging cost-effective at commonly accepted threshold levels (20,000 pounds and 30,000 pounds per QALY). Sensitivity analyses of several parameters including prevalence of psychosis were performed. RESULTS: The systematic review included 24 studies of a diagnostic before-after type of design evaluating the clinical benefit of CT, structural MRI or combinations in treatment-naive, first-episode or unspecified psychotic patients, including one in schizophrenia patients resistant to treatment. Also included was a review of published case reports of misidentification syndromes. Almost all evidence was in patients aged less than 65 years. In most studies, structural neuroimaging identified very little that would influence patient management that was not suspected based on a medical history and/or physical examination and there were more incidental findings. In the four MRI studies, approximately 5% of patients had findings that would influence clinical management, whereas in the CT studies, approximately 0.5% of patients had these findings. The review of misidentification syndromes found that 25% of CT scans affected clinical management, but this may have been a selected and therefore unrepresentative sample. A threshold analysis with a 1-year time horizon was undertaken. This combined the incremental cost of routine scanning with a threshold cost per QALY value of 20,000 pounds and 30,000 pounds to predict the QoL gain required to meet these threshold values. Routine scanning versus selective scanning appears to produce different results for MRI and CT. With MRI scanning the incremental cost is positive, ranging from 37 pounds to 150 pounds; however, when scanning routinely using CT, the result is cost saving, ranging from 7 pounds to 108 pounds with the assumption of a 1% prevalence rate of tumours/cysts or other organic causes amenable to treatment. This means that for the intervention to be viewed as cost-effective, the QALY gain necessary for MRI scanning is 0.002-0.007 and with CT scanning the QALY loss that can be tolerated is between 0.0003 and 0.0054 using a 20,000 pounds threshold value. These estimates were subjected to sensitivity analysis. With a 3-month time delay, MRI remains cost-incurring with a small gain in QoL required for the intervention to be cost-effective; routine scanning with CT remains cost-saving. When the sensitivity of CT is varied to 50%, routine scanning is both cost-incurring or cost-saving depending on the scenario. Finally, the results have been shown to be sensitive to the assumed prevalence rate of brain tumours in a psychotic population. CONCLUSIONS: The evidence to date suggests that if screening with structural neuroimaging was implemented in all patients presenting with psychotic symptoms, little would be found to affect clinical management in addition to that suspected by a full clinical history and neurological examination. From an economic perspective, the outcome is not clear. The strategy of neuroimaging for all is either cost-incurring or cost-saving (dependent upon whether MRI or CT is used) if the prevalence of organic causes is around 1%. However, these values are nested within a number of assumptions, and so have to be interpreted with caution. The main research priorities are to monitor the current use of structural neuroimaging in psychosis in the NHS to identify clinical triggers to its current use and subsequent outcomes; to undertake well-conducted diagnostic before-and-after studies on representative populations to determine the clinical utility of structural neuroimaging in this patient group, and to determine whether the most appropriate structural imaging modality in psychosis should be CT or MRI. ( view less ) Jamie J R Frew,Matthew L Clarke,Ulrich Mayer,Hendrik Van Rensburg,Robert P ToozeSome new bulky fluorinated diphosphines have been prepared and converted to palladium dichloride complexes that have been found to give increased regioselectivity and activity over other Pd-diphosphine systems when used as catalysts for hydroxycarbonylation of styrene. Ian J Frew,Wilhelm KrekMutations in the von Hippel-Lindau tumor suppressor gene VHL occur in various inherited and sporadically occurring tumors. The protein encoded by VHL--pVHL--bears no known enzymatic activities but interacts with numerous protein partners. With the identification of distinct pVHL-containing multipro... ( view more )tein complexes, a refined portrait of pVHL tumor suppressor function has arisen. In general, pVHL acts as a multipurpose adaptor protein that controls a diverse array of gene expression programs, as well as extracellular matrix assembly and microtubule-based processes, by linking various target proteins to appropriate enzymatic activities. These findings provide an evermore complex but coherent view of how pVHL functions molecularly and of the consequences of dysregulation of these diverse molecular activities on tumor formation. ( view less ) F E R Simons,A J Frew,I J Ansotegui,B S Bochner,D B K Golden,F D Finkelman,D Y M Leung,J Lotvall,G Marone,D D Metcalfe,U Müller,L J Rosenwasser,H A Sampson,L B Schwartz,M van Hage,A F WallsEffector mechanisms in anaphylaxis were reviewed. Current approaches to confirmation of the clinical diagnosis were discussed. Improved methods for distinguishing between allergen sensitization (which is common in the general population) and clinical risk of anaphylaxis (which is uncommon) were del... ( view more )iberated. Innovative techniques that will improve risk assessment in anaphylaxis in the future were described. ( view less ) Ian J Frew,Wilhelm KrekFunctional inactivation of the von Hippel-Lindau (VHL) tumour suppressor gene product, pVHL, leads to cancer in humans. It is widely accepted that pVHL functions to destabilise hypoxia inducible factor alpha (HIFalpha) subunits, key effectors of the hypoxia signalling pathway. However, growing evid... ( view more )ence indicates that tumour suppression by pVHL also involves the control of a wide variety of HIFalpha-independent processes including microtubule dynamics, primary cilium maintenance, cell proliferation, neuronal apoptosis, extracellular matrix deposition and responses to DNA damage. Moreover, it is becoming apparent that tumour initiation requires not only VHL mutation but also the alteration of additional cooperating cancer pathways. These studies are beginning to provide insights into the signalling networks involving pVHL that normally control diverse cellular processes and how disruption of these networks leads to tumour formation. ( view less ) R J Powell,A J Frew,C J Corrigan,S R Durham BACKGROUND: Treatment of allergic rhinitis with subcutaneous allergen immunotherapy is effective in terms of reductions in symptoms and seasonal use of reliever medication. Its effect on quality of life (QoL), reflecting the impact of symptoms on work/school performance and leisure activities is, h... ( view more )owever, important and often overlooked. AIMS OF THE STUDY: To assess effect on QoL of specific immunotherapy with two doses of Alutard SQ Phleum pratense in patients with moderately to severe seasonal allergic rhinoconjunctivitis inadequately controlled by standard drug therapy. METHODS: Double-blind, randomized, placebo-controlled study of 410 patients with seasonal allergic rhinoconjunctivitis. Participants were randomized (2 : 1 : 1) to receive Alutard SQ P. pratense (ALK-Abelló) at maintenance doses of 100,000 SQ-U (203 subjects), 10,000 SQ-U (104 subjects) or placebo (103 subjects) given by subcutaneous injections. The groups were well matched for demographics and baseline symptoms. Quality of life was assessed using the Rhinoconjunctivitis Quality of Life Questionnaire which covers seven domains of health before and in the peak of the pollen season. RESULTS: While all domain scores were significantly improved when comparing 100,000 SQ-U with placebo, two domain scores were significantly improved when comparing 10,000 SQ-U with placebo. When comparing 100,000 SQ-U with 10,000 SQ-U, four domain scores were significantly improved. CONCLUSION: Treatment with Alutard SQ significantly improved the seasonal QoL of patients suffering from allergic rhinoconjunctivitis. The improvement was more pronounced and wider ranging in patients who received the higher 100,000 SQ-U maintenance dose. ( view less ) Ashley K Frew,Peter D Drummond Opioid neurotransmission modulates pain and negative affect during psychological stress. To determine whether these effects differ between men and women, the opioid receptor antagonist naltrexone or placebo was administered double-blind to 21 men and 22 women before they completed 30 min of difficu... ( view more )lt mental arithmetic. To heighten negative affect, participants received seven moderately noxious electric shocks during the math task, which were believed to be contingent upon performance. Before and after the math task, participants rated pain intensity and unpleasantness while their left hand was immersed in 2 degrees C water for up to 4 min. Anxiety, discouragement and anger were also rated before, during and after the math task. Tolerance of cold-induced pain was greater in men, whereas discouragement during the math task was greater in women. Opioid blockade did not influence ratings of negative affect, which increased in line with the intensity and unpleasantness of shock-induced pain. The intensity and unpleasantness of cold-induced pain increased after the math task only in women administered naltrexone. Within the naltrexone condition, pain ratings increased most in the most discouraged subjects. However, this relationship was absent in placebo recipients, implying that the hyperalgesic effect of psychological distress was tempered by opioid release. Greater stress-evoked discouragement in women than men may explain why cold-induced pain increased after the math task only in women administered naltrexone. ( view less ) Claudio R Thoma,Ian J Frew,Wilhelm Krek Amongst other clinical manifestations, patients with the von Hippel-Lindau (VHL) cancer syndrome are predisposed to develop kidney cysts, which are considered to be precursor lesions of clear cell renal cell carcinoma (ccRCC). Recent evidence has highlighted an unexpected function of the VHL tumor ... ( view more )suppressor protein (pVHL) in maintaining the structural integrity of the primary cilium, a microtubule-based cellular antenna important for suppression of uncontrolled proliferation of kidney epithelial cells and cyst formation. Intriguingly, this function of pVHL is directly linked to its capacity to regulate the microtubule cytoskeleton independent of its well-characterized role in the degradation of hypoxia inducible factor alpha (HIFalpha) subunits. However, loss of pVHL alone does not suffice for a cell to lose the primary cilium. Other pathways need to be additionally inactivated, including one involving glycogen synthase kinase 3 beta (GSK3beta). These new findings draw attention to a primary cilium maintenance network as new territory for pVHL tumor suppressive activity and have implications for understanding the development of kidney pathology in the setting of VHL disease. ( view less ) F Estelle R Simons,Anthony J Frew,Ignacio J Ansotegui,Bruce S Bochner,David B K Golden,Fred D Finkelman,Donald Y M Leung,Jan Lotvall,Gianni Marone,Dean D Metcalfe,Ulrich Müller,Lanny J Rosenwasser,Hugh A Sampson,Lawrence B Schwartz,Marianne van Hage,Andrew F Walls Risk assessment of individuals with anaphylaxis is currently hampered by lack of (1) an optimal and readily available laboratory test to confirm the clinical diagnosis of an anaphylaxis episode and (2) an optimal method of distinguishing allergen-sensitized individuals who are clinically tolerant f... ( view more )rom those at risk for anaphylaxis episodes after exposure to the relevant allergen. Our objectives were to review the effector mechanisms involved in the pathophysiology of anaphylaxis; to explore the possibility of developing an optimal laboratory test to confirm the diagnosis of an anaphylaxis episode, and the possibility of improving methods to distinguish allergen sensitization from clinical reactivity; and to develop a research agenda for risk assessment in anaphylaxis. Researchers from the American Academy of Allergy, Asthma & Immunology and the European Academy of Allergology and Clinical Immunology held a PRACTALL (Practical Allergy) meeting to discuss these objectives. New approaches being investigated to support the clinical diagnosis of anaphylaxis include serial measurements of total tryptase in serum during an anaphylaxis episode, and measurement of baseline total tryptase levels after the episode. Greater availability of the test for mature beta-tryptase, a more specific mast cell activation marker for anaphylaxis than total tryptase, is needed. Measurement of chymase, mast cell carboxypeptidase A3, platelet-activating factor, and other mast cell products may prove to be useful. Consideration should be given to measuring a panel of mediators from mast cells and basophils. New approaches being investigated to help distinguish sensitized individuals at minimum or no risk from those at increased risk of developing anaphylaxis include measurement of the ratio of allergen-specific IgE to total IgE, determination of IgE directed at specific allergenic epitopes, measurement of basophil activation markers by using flow cytometry, and assessment of allergen-specific cytokine responses. Algorithms have been developed for risk assessment of individuals with anaphylaxis, along with a research agenda for studies that could lead to an improved ability to confirm the clinical diagnosis of anaphylaxis and to identify allergen-sensitized individuals who are at increased risk of anaphylaxis. ( view less ) Neil C Henderson,Katharine J Pollock,John Frew,Alison C Mackinnon,Richard A Flavell,Roger J Davis,Tariq Sethi,Kenneth J Simpson BACKGROUND: Acute hepatic failure secondary to paracetamol poisoning is associated with high mortality. C-jun (NH2) terminal kinase (JNK) is a member of the mitogen-activated protein kinase family and is a key intracellular signalling molecule involved in controlling the fate of cells. AIM: To exam... ( view more )ine the role of JNK in paracetamol-induced acute liver failure (ALF). METHODS: A previously developed mouse model of paracetamol poisoning was used to examine the role of JNK in paracetamol-induced ALF. RESULTS: Paracetamol-induced hepatic JNK activation both in human and murine paracetamol hepatotoxicity and in our murine model preceded the onset of hepatocyte death. JNK inhibition in vivo (using two JNK inhibitors with different mechanisms of action) markedly reduced mortality in murine paracetamol hepatotoxicity, with a significant reduction in hepatic necrosis and apoptosis. In addition, delayed administration of the JNK inhibitor was more effective than N-acetylcysteine after paracetamol poisoning in mice. JNK inhibition was not protective in acute carbon tetrachloride-mediated or anti-Fas antibody-mediated hepatic injury, suggesting specificity for the role of JNK in paracetamol hepatotoxicity. Furthermore, disruption of the JNK1 or JNK2 genes did not protect against paracetamol-induced hepatic damage. Pharmacological JNK inhibition had no effect on paracetamol metabolism, but markedly inhibited hepatic tumour necrosis foctor alpha (TNF alpha) production after paracetamol poisoning. CONCLUSIONS: These data demonstrated a central role for JNK in the pathogenesis of paracetamol-induced liver failure, thereby identifying JNK as an important therapeutic target in the treatment of paracetamol hepatotoxicity. ( view less ) R K Lindemann,A Newbold,K F Whitecross,L A Cluse,A J Frew,L Ellis,S Williams,A P Wiegmans,A E Dear,C L Scott,M Pellegrini,A Wei,V M Richon,Paul A Marks,S W Lowe,M J Smyth,R W Johnstone Histone deacetylase inhibitors (HDACi) can elicit a range of biological responses that affect tumor growth and survival, including inhibition of cell cycle progression, induction of tumor cell-selective apoptosis, suppression of angiogenesis, and modulation of immune responses, and show promising a... ( view more )ctivity against hematological malignancies in clinical trials. Using the Emu-myc model of B cell lymphoma, we screened tumors with defined genetic alterations in apoptotic pathways for therapeutic responsiveness to the HDACi vorinostat. We demonstrated a direct correlation between induction of tumor cell apoptosis in vivo and therapeutic efficacy. Vorinostat did not require p53 activity or a functional death receptor pathway to kill Emu-myc lymphomas and mediate a therapeutic response but depended on activation of the intrinsic apoptotic pathway with the proapoptotic BH3-only proteins Bid and Bim playing an important role. Our studies provide important information regarding the mechanisms of action of HDACi that have broad implications regarding stratification of patients receiving HDACi therapy alone or in combination with other anticancer agents. ( view less ) J L Brown,A F Behndig,B E Sekerel,J Pourazar,A Blomberg,F J Kelly,T Sandström,A J Frew,S J Wilson BACKGROUND: Allergic rhinitis (AR) and asthma represent a continuum of atopic disease. AR is believed to pre-dispose an individual to asthma. Compared with asthmatics and normal controls, the inflammatory response in the lower airways of rhinitics is not fully elucidated. To test the hypothesis tha... ( view more )t the inflammatory response in the airways of subjects with AR is at a level intermediate between that in normal controls and asthmatics, we have characterized bronchial inflammation and cytokine mRNA levels in non-asthmatic allergic rhinitics and compared it with subjects with allergic asthma and with normal controls. METHODS: Endobronchial mucosal biopsies were obtained at bronchoscopy from 14 allergic rhinitics, 16 asthmatics and 21 normal controls. Biopsies were embedded into glycol methacrylate resin for immunohistochemical analysis of cellular inflammation and snap frozen for semi-quantitative PCR analysis of cytokine mRNA levels. RESULTS: Airway inflammation in rhinitic subjects was characterized by an increase in submucosal eosinophils, mast cells and the mRNA expression of TNF-alpha, at an intermediate level between healthy and asthmatics. In addition, CD3(+) and CD8(+) lymphocytes in the epithelium, the endothelial expression of vascular adhesion molecule-1 and IL-1 beta mRNA were higher in the allergic rhinitics compared with both normal controls and asthmatics, whereas growth-related oncogene alpha-mRNA was decreased in AR compared with both healthy and asthmatics. Airway inflammation in the asthmatic group was characterized by higher numbers of eosinophils and mast cells, together with an increase in TNF-alpha-mRNA compared with both healthy and rhinitics. IFN-gamma mRNA was the highest in normal controls and lowest in the asthmatics. CONCLUSIONS: In individuals with AR the present data suggest an intermediate state of airway inflammation between that observed in normal individuals and subjects with clinical asthma. It is also indicated that IFN-gamma production by CD8(+) T lymphocytes could be protective against the development of airway hyperresponsiveness. Further work is needed to evaluate this hypothesis. ( view less ) Claudio R Thoma,Ian J Frew,Christian R Hoerner,Matteo Montani,Holger Moch,Wilhelm Krek Defects in the structure or function of the primary cilium, an antennae-like structure whose functional integrity has been linked to the suppression of uncontrolled kidney epithelial cell proliferation, are a common feature of genetic disorders characterized by kidney cysts. However, the mechanisms... ( view more ) by which primary cilia are maintained remain poorly defined. von Hippel-Lindau (VHL) disease is characterized by the development of premalignant renal cysts and arises because of functional inactivation of the VHL tumour suppressor gene product, pVHL. Here, we show that pVHL and glycogen synthase kinase (GSK)3beta are key components of an interlinked signalling pathway that maintains the primary cilium. Although inactivation of either pVHL or GSK3beta alone did not affect cilia maintenance, their combined inactivation leads to loss of cilia. In VHL patients, GSK3beta is subjected to inhibitory phosphorylation in renal cysts, but not in early VHL mutant lesions, and these cysts exhibit reduced frequencies of primary cilia. We propose that pVHL and GSK3beta function together in a ciliary-maintenance signalling network, disruption of which enhances the vulnerability of cells to lose their cilia, thereby promoting cyst formation. ( view less ) N Salamon,N Sicotte,A Drain,A Frew,J R Alger,J Jen,S Perlman,G Salamon Diffusion tensor imaging (DTI) color mapping and fiber tractography was used to study the white matter within the cerebellum along with the afferent and efferent tracts associated with the cerebellum in 24 normal human subjects. The most prominent structures that can be readily identified using the... ( view more )se DTI techniques are the middle, inferior and superior cerebellar peduncles. Furthermore DTI shows transverse white matter fiber that cross between the two cerebellar hemispheres at the level of the vermis. At the hemispheric level fibers to the dentate, to the emboliform nuclei are clearly visible on DTI as is the afferent pathway represented by the middle cerebellar peduncle. Selective DTI fiber tractography provides very exquisite images of the cerebellar peduncles and of the fibers projecting to and from the cerebellar cortex. This study demonstrates that DTI is complementary to conventional MRI in that DTI elucidates the orientation of white matter fiber bundles that are associated with the cerebellum. Therefore we anticipate that DTI will become an important adjunct to conventional MRI for clinical and basic studies of cerebellar ataxias and congenital disorders involving the cerebellum and brain stem. This work provides a summary of the normal DTI appearance of the cerebellar white matter which will be useful for interpreting DTI results in clinical populations. ( view less ) C R Harvey,R Frew,D Massicotte,F Péronnet,N J Rehrer Plasma glucose and muscle glycogen oxidation during prolonged exercise [75-min at 48 and 76% maximal O(2) uptake (Vo(2 max))] were measured in eight well-trained male subjects [Vo(2 max) = 4.50 l/min (SD 0.63)] using a simplified tracer technique in which a small amount of glucose highly enriched i... ( view more )n (13)C was ingested: plasma glucose oxidation was computed from (13)C/(12)C in plasma glucose (which was stable beginning at minute 30 and minute 15 during exercise at 48 and 76% Vo(2 max), respectively) and (13)CO(2) production, and muscle glycogen oxidation was estimated by subtracting plasma glucose oxidation from total carbohydrate oxidation. Consistent data from the literature suggest that this small dose of exogenous glucose does not modify muscle glycogen oxidation and has little effect, if any, on plasma glucose oxidation. The percent contributions of plasma glucose and muscle glycogen oxidation to the energy yield at 48% Vo(2 max) [15.1% (SD 3.8) and 45.9% (SD 5.8)] and at 76% Vo(2 max) [15.4% (SD 3.6) and 59.8% (SD 9.2)] were well in line with data previously reported for similar work loads and exercise durations using conventional tracer techniques. The significant reduction in glycogen concentration measured from pre- and postexercise vastus lateralis muscle biopsies paralleled muscle glycogen oxidation calculated using the tracer technique and was larger at 76% than at 48% Vo(2 max). However, the correlation coefficients between these two estimates of muscle glycogen utilization were not different from zero at each of the two work loads. The simplified tracer technique used in the present experiment appears to be a valid alternative approach to the traditional tracer techniques for computing plasma glucose and muscle glycogen oxidation during prolonged exercise. ( view less ) M Connock,A Juarez-Garcia,S Jowett,E Frew,Z Liu,R J Taylor,A Fry-Smith,E Day,N Lintzeris,T Roberts,A Burls,R S Taylor OBJECTIVES: To assess the clinical effectiveness and cost-effectiveness of buprenorphine maintenance therapy (BMT) and methadone maintenance therapy (MMT) for the management of opioid-dependent individuals. DATA SOURCES: Major electronic databases were searched from inception to August 2005. Indust... ( view more )ry submissions to the National Institute for Health and Clinical Excellence were accessed. REVIEW METHODS: The assessment of clinical effectiveness was based on a review of existing reviews plus an updated search for randomised controlled trials (RCTs). A decision tree with Monte Carlo simulation model was developed to assess the cost-effectiveness of BMT and MMT. Retention in treatment and opiate abuse parameters were sourced from the meta-analysis of RCTs directly comparing flexible MMT with flexible dose BMT. Utilities were derived from a panel representing a societal perspective. RESULTS: Most of the included systematic reviews and RCTs were of moderate to good quality, and focused on short-term (up to 1-year follow-up) outcomes of retention in treatment and the level of opiate use (self-report or urinalysis). Most studies employed a trial design that compared a fixed-dose strategy (i.e. all individuals received a standard dose) of MMT or BMT and were conducted in predominantly young men who fulfilled criteria as opiate-dependent or heroin-dependent users, without significant co-morbidities. RCT meta-analyses have shown that a fixed dose of MMT or BMT has superior levels of retention in treatment and opiate use than placebo or no treatment, with higher fixed doses being more effective than lower fixed doses. There was evidence, primarily from non-randomised observational studies, that fixed-dose MMT reduces mortality, HIV risk behaviour and levels of crime compared with no therapy and one small RCT has shown the level of mortality with fixed-dose BMT to be significantly less than with placebo. Flexible dosing (i.e. individualised doses) of MMT and BMT is more reflective of real-world practice. Retention in treatment was superior for flexible MMT than flexible BMT dosing but there was no significant difference in opiate use. Indirect comparison of data from population cross-sectional studies suggests that mortality with BMT may be lower than that with MMT. A pooled RCT analysis showed no significant difference in serious adverse events with MMT compared with BMT. Although treatment modifier evidence was limited, adjunct psychosocial and contingency interventions (e.g. financial incentives for opiate-free urine samples) appeared to enhance the effects of both MMT and BMT. Also, MMT and BMT appear to be similarly effective whether delivered in a primary care or outpatient clinic setting. Although most of the included economic evaluations were considered to be of high quality, none used all of the appropriate parameters, effectiveness data, perspective and comparators required to make their results generalisable to the NHS context. One company (Schering-Plough) submitted cost-effectiveness evidence based on an economic model that had a 1-year time horizon and sourced data from a single RCT of flexible-dose MMT compared with flexible-dose BMT and utility values obtained from the literature; the results showed that for MMT vs no drug therapy, the incremental cost-effectiveness ratio (ICER) was pound 12,584/quality-adjusted life-year (QALY), for BMT versus no drug therapy, the ICER was pound 30,048/QALY and in a direct comparison, MMT was found to be slightly more effective and less costly than BMT. The assessment group model found for MMT versus no drug therapy that the ICER was pound 13,697/QALY, for BMT versus no drug therapy that the ICER was pound 26,429/QALY and, as with the industry model, in direct comparison, MMT was slightly more effective and less costly than BMT. When considering social costs, both MMT and BMT gave more health gain and were less costly than no drug treatment. These findings were robust to deterministic and probabilistic sensitivity analyses. CONCLUSIONS: Both flexible-dose MMT and BMT are more clinically effective and more cost-effective than no drug therapy in dependent opiate users. In direct comparison, a flexible dosing strategy with MMT was found be somewhat more effective in maintaining individuals in treatment than flexible-dose BMT and therefore associated with a slightly higher health gain and lower costs. However, this needs to be balanced by the more recent experience of clinicians in the use of buprenorphine, the possible risk of higher mortality of MMT and individual opiate-dependent users' preferences. Future research should be directed towards the safety and effectiveness of MMT and BMT; potential safety concerns regarding methadone and buprenorphine, specifically mortality and key drug interactions; efficacy of substitution medications (in particular patient subgroups, such as within the criminal justice system, or within young people); and uncertainties in cost-effectiveness identified by current economic models. ( view less ) Emma J Frew,Josie Sandercock,William P Whitehouse,Stirling Bryan PURPOSE: Epilepsies in children are complex diseases. Guidelines are needed on the appropriate use of newer versus older anti-epileptic drugs (AEDs). This paper presents an individual patient-sampling model to assess the cost-effectiveness of using newer AEDs as add-on therapy in line with UK presc... ( view more )ribing guidance. METHODS: Identification of the relevant parameters and treatment pathways for the model were achieved by a systematic review of the literature and discussions with clinical experts. Data were obtained from the literature and supplemented with data elicited from paediatric neurologists. The model considered paediatric patients over the period of childhood from the age of diagnosis to 18 years. RESULTS: The results suggest that the older and newer AEDs are similar in terms of drug retention rates and the average time in 'good' treatment outcomes. In terms of cost, the results indicate a consistent increase in cost (compared to older AEDs) when all of the newer AEDs are considered. The decision analysis results indicate that there are no important health benefits from the use of newer AEDs when used as add-on therapy. However, the analysis also reveals that the uncertainties in the model are greater than the differences between the drug strategies. CONCLUSIONS: To develop guidelines on the appropriate use of newer AEDs, better information is required from randomised controlled trials as there is insufficient data available in the public domain to accurately estimate the nature of the trade off between older versus newer AEDs. ( view less ) Bruce E Katz,Sarah Truong,Diane C Maiwald,Kathryn E Frew,Dean GeorgeTopical 5-aminolevulinic acid (ALA) and various light sources have been used to treat actinic keratoses and acne. Many of these regimens have required long incubation times due to the penetration qualities of ALA. This study tested the effectiveness of ALA in producing erythema when applied for 10 ... ( view more )minutes after 2 passes of microdermabrasion versus an incubation time of one hour without microdermabrasion. The areas were treated with a 595-nm pulsed dye laser at 15 J/cm2 or 22.5 J/cm2. Photographs were taken at 24 and 48 hours after the treatment. The data indicated consistent superior results with the use of microdermabrasion prior to the application of ALA for 10 minutes. It appears that incubation of ALA with microdermabrasion for 10 minutes is as effective as, or more so than, ALA applied alone for one hour in producing erythema. ( view less ) Y Adi,A Juarez-Garcia,D Wang,S Jowett,E Frew,E Day,S Bayliss,T Roberts,A Burls OBJECTIVES: To investigate the clinical effectiveness and cost-effectiveness of naltrexone for relapse prevention in detoxified formerly opioid-dependent individuals compared with any strategy that does not use naltrexone, including treatment with placebo, other pharmacological treatments, psychoso... ( view more )cial interventions or no treatment. DATA SOURCES: Major electronic databases were searched from inception to September 2005. REVIEW METHODS: Selected studies were screened and quality assessed. Meta-analyses were carried out as appropriate. A decision-analytic model using Monte Carlo simulation was developed that compared naltrexone as an adjunctive therapy to no naltrexone. It assumed compliance rates that were not enhanced by contingent management rewards (because this is current UK practice). Utility values could not be identified from the literature and so were obtained by research specially commissioned from the Value of Health Panel. RESULTS: The methodological quality of the 26 randomised controlled trials (RCTs) that met the inclusion criteria was poor to moderate. The results suggest that naltrexone as maintenance therapy may be better than placebo in terms of retention in treatment, but this was not statistically significant. A meta-analysis of seven included RCTs gave the relative risk (RR) of loss of retention in treatment in the naltrexone arm as 0.94. The pooled hazard ratio (HR) reported in five of the RCTs for retention in treatment data followed up to 35 weeks was calculated as 0.90 in favour of naltrexone and also did not reach statistical significance. The risk of drug abuse in naltrexone versus placebo, with or without psychological support given in both arms, gave a pooled RR of 0.72, which was a statistically significant difference in favour of naltrexone. The pooled HR from three RCTs for opioid relapse-free rates was significantly different from placebo in favour of naltrexone 0.53; however, this fell off over time and may be of limited clinical significance. The RR of reimprisonment while on naltrexone therapy showed results in favour of naltrexone in the combined two studies of parolees or people on probation, but the number of participants was small. One study of 52 participants found that the difference in improvement score for risky sexual behaviour in the naltrexone group compared with the placebo group was not statistically significant. The adverse events data reported showed no significant difference between the naltrexone and placebo arms. The quality of the nine RCTs of interventions designed to increase retention with naltrexone was poor to moderate; however, all three different modalities of enhanced care showed some evidence of effectiveness. All of the contingency management programmes used incentive vouchers; the mean duration of treatment retention was 7.4 weeks for the contingency management intervention compared with 2.3-5.6 weeks for the naltrexone treatment alone. The mean length of time for which patients stayed on naltrexone was 84-103 days with additional psychosocial therapy compared with 43-64 days for the control group. In trials with added pharmacological agents the RRs of stopping treatment were 1.63 at 6 months and 1.31 at 12 months (in favour of naltrexone plus fluoxetine). It became statistically significant at 6 months, but not at 12 months. A meta-analysis of the RR of stopping treatment at week 12 (the minimum follow-up period) was carried out using six of the nine studies. The pooled RR of stopping treatment was 0.81. The results indicated that overall the intervention groups had 19% fewer patients who stopped treatment compared with the control group, but there was only a small number of studies and their quality was relatively poor. No existing economic evaluations were identified. The point estimate for the cost-effectiveness of naltrexone was pound42,500 per quality-adjusted life-year (QALY). Sensitivity analysis was carried out and the incremental cost-effectiveness ratio varied between pound34,600 and pound42,500 per QALY gained. CONCLUSIONS: Following successful withdrawal from opioids, naltrexone may be administered on a chronic basis to block any future effects of opioids. Naltrexone appears to have some limited benefit in helping formerly opioid-dependent individuals to remain abstinent, although the quality of the evidence is relatively poor and heterogeneous. The limited quality and extent of the studies precluded an analysis of subgroups likely to benefit from naltrexone prescribing. Oral naltrexone is used infrequently in current UK practice, and this review suggests that this is appropriate as there is little evidence to support its wider implementation. There is an important deficit in information about the quality of life of people who use illicit opioids and this would perhaps be a worthwhile area of research in informing policy questions about the cost-effectiveness of different programmes and interventions. ( view less ) P A Singer,E B Court,A Bhatt,S E Frew,H Greenwood,D L Persad,F Salamanca-Buentello,B Séguin,A D Taylor,H T Daer,A S Daar While the past century has seen significant improvement in life expectancies in the developed world, it has also witnessed diseases like HIV/AIDS, malaria and tuberculosis ravage populations in the developing world. In some Sub-Saharan African countries, life expectancies have plummeted to less tha... ( view more )n 40 years--nearly half of those in developed countries. Unequal access to the benefits of science and technology, including medical advances, exacerbate this disparity. In order to address the challenge of global health inequities and strengthen the role of science and technology innovation in contributing to real solutions, the Canadian Program on Genomics and Global health (CPGGH), based at the University of Toronto, has identified three guiding questions: Which genomics-related technologies are most likely to improve the health of people in developing countries?; How can developing countries harness these technologies for health development?; and What can industrialized countries do to assist developing countries? ( view less ) Ming Yang,Danny Rangasamy,Klaus I Matthaei,Ailsa J Frew,Nives Zimmmermann,Suresh Mahalingam,Dianne C Webb,David J Tremethick,Philip J Thompson,Simon P Hogan,Marc E Rothenberg,William B Cowden,Paul S Foster Increased arginase I activity is associated with allergic disorders such as asthma. How arginase I contributes to and is regulated by allergic inflammatory processes remains unknown. CD4+ Th2 lymphocytes (Th2 cells) and IL-13 are two crucial immune regulators that use STAT6-dependent pathways to in... ( view more )duce allergic airways inflammation and enhanced airways responsiveness to spasmogens (airways hyperresponsiveness (AHR)). This pathway is also used to activate arginase I in isolated cells and in hepatic infection with helminths. In the present study, we show that arginase I expression is also regulated in the lung in a STAT6-dependent manner by Th2-induced allergic inflammation or by IL-13 alone. IL-13-induced expression of arginase I correlated directly with increased synthesis of urea and with reduced synthesis of NO. Expression of arginase I, but not eosinophilia or mucus hypersecretion, temporally correlated with the development, persistence, and resolution of IL-13-induced AHR. Pharmacological supplementation with l-arginine or with NO donors amplified or attenuated IL-13-induced AHR, respectively. Moreover, inducing loss of function of arginase I specifically in the lung by using RNA interference abrogated the development of IL-13-induced AHR. These data suggest an important role for metabolism of l-arginine by arginase I in the modulation of IL-13-induced AHR and identify a potential pathway distal to cytokine receptor interactions for the control of IL-13-mediated bronchoconstriction in asthma. ( view less ) M Connock,A Burls,E Frew,A Fry-Smith,A Juarez-Garcia,C McCabe,A Wailoo,K Abrams,N Cooper,A Sutton,A O'Hagan,D Moore OBJECTIVES: The aim of this review is to determine the clinical effectiveness and cost-effectiveness of enzyme replacement therapy (ERT) in the treatment of symptomatic Gaucher's disease. DATA SOURCES: Major electronic databases were searched from their inception to August 2003; and updated from Ja... ( view more )nuary 2003 to July/August 2004. REVIEW METHODS: Databases were searched for studies that met the criteria and selected data were extracted and evaluated. Studies were assessed for their relevance to the UK context and the review objective. The bibliographic databases were also searched to identify existing cost studies, economic evaluations and models. A Markov decision model was constructed based on patients moving between states defined by the modified Severity Score Index (SSI). Most of the parameters were derived from the published literature. ERT was assumed to restore patients to full health in the base case. RESULTS: Sixty-three studies were included, all suggestive of benefit with ERT. However, the way in which the effects translate into patient well-being and survival or the need for services and resources has not been reliably estimated. Quality of life improvements with ERT have been reported. Nonetheless, studies based on the Short Form 36 (SF-36) indicate that patients treated with ERT continue to have reduced health-related quality of life (HRQoL) compared with the general population. No study attached utility values to quality of life measures for ERT-treated patients. Thirty-one studies relevant to the natural history of the disease were found. Sixteen looked at multiple clinical characteristics of a cohort of patients with type I Gaucher's disease. There was considerable within-study and between-study heterogeneity, but all showed that Gaucher's disease was a progressive condition. Some suggested that the disease may become more indolent in adulthood; however, studies were discrepant on this point. Most disease is diagnosed in adulthood, although about one-quarter presented in childhood, these patients having the most severe symptoms and greatest rate of progression. Modelling of natural history was undertaken using the five papers that reported the SSI for each patient, along with patient-level data on age, age at diagnosis, splenectomy status and genotype, to address the question of whether disease stabilises in adulthood and the degree of correlation between phenotype and genotype. Analysis of the available data suggested that disease progression is likely to slow markedly in adulthood and that genotype is a useful predictor of clinical expression of the disease. Five studies looked at quality of life. Data on this topic were also obtained from the registries. The evidence suggests that the vast majority of the clinical characteristics of type I Gaucher's disease have little impact on subjective HRQoL and that therefore for the majority of people with type I Gaucher's disease this may not be a severe condition. Bone and skeletal symptoms contribute most to the morbidity of the disease and can lead to severe pain and immobility. The mean cost per patient treated was approximately pounds sterling 86,000 per annum in England and Wales. The cost per patient varied considerably by dose. Four existing economic evaluations were found, all of which calculated a very high cost per quality-adjusted life-year (QALY). Using the Markov decision model, ERT was assumed to restore patients to full health in the base case. The estimated incremental cost per QALY [incremental cost-effectiveness ratio (ICER)] in the base case ranged from pounds sterling 380,000 to pounds sterling 476,000 per QALY, depending on genotype. Univariate sensitivity analyses examined ERT not restoring full health, more severe disease progression in the untreated cohort, and only treating the most severely affected patients. These produced ICERs of approximately pounds sterling 1.4 million, pounds sterling 296,000 and pounds sterling 275,000 per QALY, respectively. The base-case unit cost of the drug is pounds sterling 2.975. The unit cost would have had to be reduced ten-fold, to pounds sterling 0.30, to obtain an ICER of pounds sterling 30,000 per QALY. At a unit cost of pounds sterling 1 the ICER would be pounds sterling 120,000 per QALY. CONCLUSIONS: Although ERT for treating the 'average' Gaucher's disease patient exceeds the normal upper threshold for cost-effectiveness seen in NHS policy decisions by over ten-fold, some argue that since orphan drug legislation encouraged the manufacture of Cerezyme, and Gaucher's disease can be defined as an orphan disease, the NHS has little option but to provide it, despite its great expense. More information is required before the generalisability of the findings can be determined. Although data from the UK have been used wherever possible, these were very thin indeed. Nonetheless, even large errors in estimates of the distribution of genotype, genotype--phenotype associations, effectiveness and numbers of patients will not reduce the ICER to anywhere near the upper level of treatments usually considered cost-effective. Further research could help to clarify the many uncertainties that exist. However, although doing so will be of clinical interest, it is questionable whether, within the current pricing environment, such research would have any substantive impact on policy decisions. It is highly improbable that, whatever the findings of such research, the ICER could be brought down by the orders of magnitude required to make ERT an efficient use of health service resources. (The possible exception to this would be investigating the most efficient alternative treatment strategies for using ERT in a paediatric population only.) Moreover, if under equity considerations for orphan diseases the NHS feels it is important to provide this drug, regardless of its cost-effectiveness, then refining the precision of the ICER estimate also becomes superfluous. ( view less ) A A Maudsley,A Darkazanli,J R Alger,L O Hall,N Schuff,C Studholme,Y Yu,A Ebel,A Frew,D Goldgof,Y Gu,R Pagare,F Rousseau,K Sivasankaran,B J Soher,P Weber,K Young,X Zhu Image reconstruction for magnetic resonance spectroscopic imaging (MRSI) requires specialized spatial and spectral data processing methods and benefits from the use of several sources of prior information that are not commonly available, including MRI-derived tissue segmentation, morphological anal... ( view more )ysis and spectral characteristics of the observed metabolites. In addition, incorporating information obtained from MRI data can enhance the display of low-resolution metabolite images and multiparametric and regional statistical analysis methods can improve detection of altered metabolite distributions. As a result, full MRSI processing and analysis can involve multiple processing steps and several different data types. In this paper, a processing environment is described that integrates and automates these data processing and analysis functions for imaging of proton metabolite distributions in the normal human brain. The capabilities include normalization of metabolite signal intensities and transformation into a common spatial reference frame, thereby allowing the formation of a database of MR-measured human metabolite values as a function of acquisition, spatial and subject parameters. This development is carried out under the MIDAS project (Metabolite Imaging and Data Analysis System), which provides an integrated set of MRI and MRSI processing functions. It is anticipated that further development and distribution of these capabilities will facilitate more widespread use of MRSI for diagnostic imaging, encourage the development of standardized MRSI acquisition, processing and analysis methods and enable improved mapping of metabolite distributions in the human brain. ( view less )
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